From 39addfed12b36d1e009d08beba4cb8d5ef9946d0 Mon Sep 17 00:00:00 2001
From: Valentin Churavy <v.churavy@gmail.com>
Date: Fri, 11 Nov 2022 21:34:07 -0500
Subject: [PATCH 01/36] WIP: Add support for PCI devices

Co-authored-by: Johannes Blaschke <johannes.blaschke@gmail.com>
---
 src/libhwloc.jl | 74 +++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 60 insertions(+), 14 deletions(-)

diff --git a/src/libhwloc.jl b/src/libhwloc.jl
index dfed3b7..21fd761 100644
--- a/src/libhwloc.jl
+++ b/src/libhwloc.jl
@@ -17,12 +17,10 @@ const obj_types =
            :Bridge, :PCI_Device, :OS_Device, :Misc, :MemCache, :Die, :Error]
 const cache_types =
     Symbol[:Unified, :Data, :Instruction]
-# const bridge_types
+const bridge_types = [:Host, :PCI]
 const osdev_types =
     Symbol[:Block, :GPU, :Network, :Openfabrics, :DMA, :CoProc]
 
-
-
 struct hwloc_obj_memory_page_type_s
     size::Culonglong
     count::Culonglong
@@ -232,11 +230,11 @@ function load_attr(hattr::Ptr{Cvoid}, type_::Symbol)
     elseif type_==:Misc
         error("not implemented")
     elseif type_==:Bridge
-        error("not implemented")
+        return NullAttr()
     elseif type_==:PCI_Device
-        error("not implemented")
+        return NullAttr()
     elseif type_==:OS_Device
-        error("not implemented")
+        return NullAttr()
     elseif type_==:Die
         ha = unsafe_load(convert(Ptr{hwloc_cache_attr_s}, hattr))
         return DieAttr(ha.depth)
@@ -265,6 +263,8 @@ struct Object
     
     memory_children::Vector{Object}
 
+    io_children::Vector{Object}
+
     # Object() = new(:Error, -1, "(nothing)", NullAttr(),
     #                0, -1, -1, # -1,
     #                Object[], Object[])
@@ -321,25 +321,69 @@ function load(hobj::hwloc_obj_t)
     children = Object[load(child) for child in obj_children]
 
     memory_children = Object[]
-    if obj.memory_arity != C_NULL && obj.memory_first_child != C_NULL
+    if obj.memory_arity != 0 && obj.memory_first_child != C_NULL
         push!(memory_children, load(obj.memory_first_child))
     end
 
-    topo = Object(type_, os_index, name, attr, mem, depth, logical_index, children, memory_children)
+    io_children = Object[]
+    @show obj.io_arity
+    if obj.io_arity != 0 
+        io_child = obj.io_first_child
+        while io_child != C_NULL
+            push!(io_children, load(obj.io_first_child))
+            io_child = unsafe_load(io_child).next_sibling
+        end
+    end
+    @show io_children
+
+    topo = Object(type_, os_index, name, attr, mem, depth, logical_index, children, memory_children, io_children)
     return topo
 end
 
 
+# TODO enum
+const HWLOC_TYPE_FILTER_KEEP_ALL = Cint(0)
+const HWLOC_TYPE_FILTER_KEEP_NONE = Cint(1)
+const HWLOC_TYPE_FILTER_KEEP_STRUCTURE = Cint(2)
+const HWLOC_TYPE_FILTER_KEEP_IMPORTANT = Cint(3)
+
+function get_type_filter(topology, object_type)
+    r_type_filter = Ref{Cint}()
+    ierr = ccall((:hwloc_topology_get_type_filter, libhwloc), Cint, (Ptr{Cvoid}, Cint, Ptr{Cint}), topology, object_type, r_type_filter)
+    @assert ierr == 0
+    return r_type_filter[]
+end
+
+function set_type_filter!(topology, object_type, type_filter)
+    ierr = ccall((:hwloc_topology_set_type_filter, libhwloc), Cint, (Ptr{Cvoid}, Cint, Cint), topology, object_type, type_filter)
+    @assert ierr == 0
+    return
+end
+
+function set_io_types_filter!(htopo, filter)
+    os_filter_type = findfirst(s->s==:OS_Device, Hwloc.obj_types) - 1
+    set_type_filter!(htopo, os_filter_type, filter)
+    set_type_filter!(htopo, os_filter_type-1, filter)
+    set_type_filter!(htopo, os_filter_type-2, filter)
+end
+
+function topology_init()
+    r_htopo = Ref{Ptr{Cvoid}}()
+    ierr = ccall((:hwloc_topology_init, libhwloc), Cint, (Ptr{Ptr{Cvoid}},), r_htopo)
+    @assert ierr == 0
+    return r_htopo[]
+end
+
+function topology_destroy(htopo)
+    ccall((:hwloc_topology_destroy, libhwloc), Cvoid, (Ptr{Cvoid},), htopo)
+end
+
 """
     topology_load() -> Hwloc.Object
 
 Load the system topology by calling into libhwloc.
 """
-function topology_load()
-    htopop = Ref{Ptr{Cvoid}}()
-    ierr = ccall((:hwloc_topology_init, libhwloc), Cint, (Ptr{Cvoid},), htopop)
-    @assert ierr==0
-    htopo = htopop[]
+function topology_load(htopo=topology_init(); destroy=true)
     ierr = ccall((:hwloc_topology_load, libhwloc), Cint, (Ptr{Cvoid},), htopo)
     @assert ierr==0
 
@@ -353,7 +397,9 @@ function topology_load()
                  (Ptr{Cvoid}, Cuint, Cuint), htopo, 0, 0)
     topo = load(root)
 
-    ccall((:hwloc_topology_destroy, libhwloc), Cvoid, (Ptr{Cvoid},), htopo)
+    if destroy
+        topology_destroy(htopo)
+    end
 
     return topo
 end
\ No newline at end of file

From 92310dac29e76ceb31abc54074ab7ab6a2f42dcf Mon Sep 17 00:00:00 2001
From: Valentin Churavy <v.churavy@gmail.com>
Date: Sun, 13 Nov 2022 14:59:49 -0500
Subject: [PATCH 02/36] fixup! WIP: Add support for PCI devices

---
 src/libhwloc.jl | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/libhwloc.jl b/src/libhwloc.jl
index 21fd761..b24a3aa 100644
--- a/src/libhwloc.jl
+++ b/src/libhwloc.jl
@@ -321,20 +321,22 @@ function load(hobj::hwloc_obj_t)
     children = Object[load(child) for child in obj_children]
 
     memory_children = Object[]
-    if obj.memory_arity != 0 && obj.memory_first_child != C_NULL
-        push!(memory_children, load(obj.memory_first_child))
+    if obj.memory_arity != 0
+        memory_child = obj.memory_first_child 
+        while memory_child != C_NULL
+            push!(memory_children, load(memory_child))
+            memory_child = unsafe_load(memory_child).next_sibling
+        end
     end
 
     io_children = Object[]
-    @show obj.io_arity
     if obj.io_arity != 0 
         io_child = obj.io_first_child
         while io_child != C_NULL
-            push!(io_children, load(obj.io_first_child))
+            push!(io_children, load(io_child))
             io_child = unsafe_load(io_child).next_sibling
         end
     end
-    @show io_children
 
     topo = Object(type_, os_index, name, attr, mem, depth, logical_index, children, memory_children, io_children)
     return topo

From 569e052c2b68f6e2544d84c170ccd69a072067e1 Mon Sep 17 00:00:00 2001
From: Valentin Churavy <v.churavy@gmail.com>
Date: Sun, 13 Nov 2022 15:08:21 -0500
Subject: [PATCH 03/36] Add PCIDevAttr

---
 src/libhwloc.jl | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/libhwloc.jl b/src/libhwloc.jl
index b24a3aa..82f3c62 100644
--- a/src/libhwloc.jl
+++ b/src/libhwloc.jl
@@ -183,6 +183,12 @@ struct PCIDevAttr <: Attribute
     revision::Int
     linkspeed::Float32
 end
+function PCIDevAttr(ha::hwloc_pcidev_attr_s)
+    return PCIDevAttr(
+        ha.domain, ha.bus, ha.dev, ha.func, ha.class_id,
+        ha.vendor_id, ha.device_id, ha.subvendor_id, ha.subdevice_id,
+        ha.revision, ha.linkspeed)
+end
 # TODO: expand this
 show(io::IO, a::PCIDevAttr) = print(io, "PCIDev{...}")
 
@@ -232,7 +238,8 @@ function load_attr(hattr::Ptr{Cvoid}, type_::Symbol)
     elseif type_==:Bridge
         return NullAttr()
     elseif type_==:PCI_Device
-        return NullAttr()
+        ha = unsafe_load(convert(Ptr{hwloc_pcidev_attr_s}, hattr))
+        return PCIDevAttr(ha)
     elseif type_==:OS_Device
         return NullAttr()
     elseif type_==:Die

From 331f9b4cc7ddcb4addd2580f8bb3c49cbc6e08e8 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Tue, 3 Jan 2023 23:08:27 +1300
Subject: [PATCH 04/36] wip on printing pci data

---
 src/highlevel_api.jl | 21 ++++++++++++++-------
 src/lowlevel_api.jl  | 14 +++++++++-----
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index d8d8329..8c1ed60 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -50,6 +50,10 @@ function print_topology(io::IO = stdout, obj::Object = gettopology(); indent = "
             print_topology(io, child; indent = indent*repeat(" ", 4), newline=true)
         end
     end
+
+    for child in obj.io_children
+        print_topology(io, child; indent=indent*repeat(" ", 4), newline=true)
+    end
     return nothing
 end
 print_topology(obj::Object) = print_topology(stdout, obj)
@@ -57,12 +61,15 @@ print_topology(obj::Object) = print_topology(stdout, obj)
 """
 Returns the top-level system topology `Object`.
 
-On first call, it loads the topology by querying
-libhwloc and caches the result.
+On first call, it loads the topology by querying libhwloc and caches the result.
+Pass `reload=true` in order to force reload.
 """
-function gettopology()
-    if !isassigned(machine_topology)
-        machine_topology[] = topology_load()
+function gettopology(htopo=nothing; reload=false)
+    if reload || (!isassigned(machine_topology))
+        if isnothing(htopo)
+            htopo=topology_init()
+        end
+        machine_topology[] = topology_load(htopo)
     end
 
     return machine_topology[]
@@ -71,7 +78,7 @@ end
 """
 Prints the system topology as a tree.
 """
-topology() = print_topology(gettopology())
+topology(htopo=nothing) = print_topology(gettopology(htopo))
 
 """
 Prints a summary of the system topology (loosely similar to `hwloc-info`).
@@ -306,6 +313,6 @@ The quality of the result might depend on the used terminal and might vary betwe
 **Note:** The specific visualization may change between minor versions.
 """
 function topology_graphical()
-    run(`$(lstopo_no_graphics()) --no-io --no-legend --of txt`)
+    run(`$(lstopo_no_graphics()) --no-legend --of txt`)
     return nothing
 end
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index e4aa6bf..ca03678 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -98,7 +98,9 @@ function PCIDevAttr(ha::hwloc_pcidev_attr_s)
         ha.revision, ha.linkspeed)
 end
 # TODO: expand this
-show(io::IO, a::PCIDevAttr) = print(io, "PCIDev{...}")
+function show(io::IO, a::PCIDevAttr)
+    print(io, "PCIDev(domain=$(a.domain), bus=$(a.bus), func=$(a.func), class_id=$(a.class_id), vendor_id=$(a.vendor_id), device_id=$(a.device_id), subvendor_id=$(a.subvendor_id), subdevice_id=$(a.subdevice_id), revision=$(a.revision), linkspeed=$(a.linkspeed))")
+end
 
 # type BridgeAttr <: Attribute end
 
@@ -234,9 +236,6 @@ function load(hobj::hwloc_obj_t)
     children = Object[load(child) for child in obj_children]
 
     memory_children = Object[]
-    # if obj.memory_arity != C_NULL && obj.memory_first_child != C_NULL
-    #     push!(memory_children, load(obj.memory_first_child))
-    # end
     if obj.memory_arity != 0
         memory_child = obj.memory_first_child 
         while memory_child != C_NULL
@@ -262,9 +261,14 @@ function load(hobj::hwloc_obj_t)
 end
 
 
-function topology_init()
+function topology_init(;get_io=true)
     r_htopo = Ref{hwloc_topology_t}()
     hwloc_topology_init(r_htopo)
+    if get_io
+        hwloc_topology_set_io_types_filter(
+            r_htopo[], LibHwloc.HWLOC_TYPE_FILTER_KEEP_ALL
+        )
+    end
     return r_htopo[]
 end
 

From 41c5f2013d452a81c5ec729e6fa89833c78f68f5 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 9 Jul 2023 22:06:52 -0700
Subject: [PATCH 05/36] wip

---
 src/libhwloc.jl     |  2 +-
 src/lowlevel_api.jl | 65 ++++++++++++++++++++++++++++++++-------------
 2 files changed, 48 insertions(+), 19 deletions(-)

diff --git a/src/libhwloc.jl b/src/libhwloc.jl
index 4855794..4510d1e 100644
--- a/src/libhwloc.jl
+++ b/src/libhwloc.jl
@@ -235,7 +235,7 @@ const hwloc_nodeset_t = hwloc_bitmap_t
 
 const hwloc_const_nodeset_t = hwloc_const_bitmap_t
 
-# TODO: doe we need this?
+# TODO: do we need this?
 # struct hwloc_obj_memory_page_type_s
 #     size::Culonglong
 #     count::Culonglong
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index ca03678..eb23754 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -2,12 +2,12 @@ using ..LibHwloc:
     hwloc_cpuset_t, hwloc_nodeset_t, hwloc_obj_type_t, hwloc_obj_cache_type_t,
     hwloc_obj_bridge_type_t, hwloc_obj_osdev_type_t, hwloc_distances_s,
     hwloc_obj, hwloc_obj_t, hwloc_obj_attr_u, hwloc_cache_attr_s,
-    hwloc_group_attr_s, hwloc_pcidev_attr_s, hwloc_osdev_attr_s,
-    hwloc_topology_t, hwloc_topology_init, hwloc_topology_load,
-    hwloc_topology_get_depth, hwloc_get_nbobjs_by_depth, hwloc_get_obj_by_depth,
-    hwloc_topology_destroy, hwloc_type_filter_e, hwloc_topology_set_type_filter,
-    hwloc_topology_get_type_filter, hwloc_topology_set_all_types_filter,
-    hwloc_topology_set_cache_types_filter,
+    hwloc_group_attr_s, hwloc_bridge_attr_s, hwloc_pcidev_attr_s,
+    hwloc_osdev_attr_s, hwloc_topology_t, hwloc_topology_init,
+    hwloc_topology_load, hwloc_topology_get_depth, hwloc_get_nbobjs_by_depth,
+    hwloc_get_obj_by_depth, hwloc_topology_destroy, hwloc_type_filter_e,
+    hwloc_topology_set_type_filter, hwloc_topology_get_type_filter,
+    hwloc_topology_set_all_types_filter, hwloc_topology_set_cache_types_filter,
     hwloc_topology_set_icache_types_filter, hwloc_topology_set_io_types_filter,
     hwloc_topology_set_userdata, hwloc_topology_get_userdata
 
@@ -42,15 +42,14 @@ for x in instances(hwloc_obj_cache_type_t)
     push!(cache_types, cenum_name_to_symbol(x, "HWLOC_OBJ_CACHE_"))
 end
 
-# const bridge_types
 bridge_types = Symbol[]
 for x in instances(hwloc_obj_bridge_type_t)
-    push!(cache_types, cenum_name_to_symbol(x, "HWLOC_OBJ_BRIDGE_"))
+    push!(bridge_types, cenum_name_to_symbol(x, "HWLOC_OBJ_BRIDGE_"))
 end
 
 osdev_types = Symbol[]
 for x in instances(hwloc_obj_osdev_type_t)
-    push!(cache_types, cenum_name_to_symbol(x, "HWLOC_OBJ_OSDEV_"))
+    push!(osdev_types, cenum_name_to_symbol(x, "HWLOC_OBJ_OSDEV_"))
 end
 
 abstract type Attribute end
@@ -67,8 +66,14 @@ struct CacheAttr <: Attribute
     type_::Symbol
 end
 function show(io::IO, a::CacheAttr)
-    print(io, "Cache{size=$(a.size),depth=$(a.depth),linesize=$(a.linesize),",
-          "associativity=$(a.associativity),type=$(string(a.type_))}")
+    print(
+        io,
+        "Cache{size=$(a.size), "             *
+        "depth=$(a.depth), "                 *
+        "linesize=$(a.linesize), "           *
+        "associativity=$(a.associativity), " *
+        "type=$(string(a.type_))}"
+    )
 end
 
 struct GroupAttr <: Attribute
@@ -93,16 +98,36 @@ struct PCIDevAttr <: Attribute
 end
 function PCIDevAttr(ha::hwloc_pcidev_attr_s)
     return PCIDevAttr(
-        ha.domain, ha.bus, ha.dev, ha.func, ha.class_id,
-        ha.vendor_id, ha.device_id, ha.subvendor_id, ha.subdevice_id,
-        ha.revision, ha.linkspeed)
+        ha.domain, ha.bus, ha.dev, ha.func, ha.class_id, ha.vendor_id,
+        ha.device_id, ha.subvendor_id, ha.subdevice_id, ha.revision,
+        ha.linkspeed
+    )
 end
-# TODO: expand this
 function show(io::IO, a::PCIDevAttr)
-    print(io, "PCIDev(domain=$(a.domain), bus=$(a.bus), func=$(a.func), class_id=$(a.class_id), vendor_id=$(a.vendor_id), device_id=$(a.device_id), subvendor_id=$(a.subvendor_id), subdevice_id=$(a.subdevice_id), revision=$(a.revision), linkspeed=$(a.linkspeed))")
+    print(
+        io,
+        "PCIDev(domain=$(a.domain), "      *
+        "bus=$(a.bus), "                   *
+        "func=$(a.func), "                 *
+        "class_id=$(a.class_id), "         *
+        "vendor_id=$(a.vendor_id), "       *
+        "device_id=$(a.device_id), "       *
+        "subvendor_id=$(a.subvendor_id), " *
+        "subdevice_id=$(a.subdevice_id), " *
+        "revision=$(a.revision), "         *
+        "linkspeed=$(a.linkspeed))"
+    )
 end
 
-# type BridgeAttr <: Attribute end
+struct BridgeAttr <: Attribute
+    data::NTuple{40, UInt8}
+end
+function BridgeAttr(ha::hwloc_bridge_attr_s)
+    return BridgeAttr(ha.data)
+end
+function show(io::IO, a::BridgeAttr)
+    print(io, "BridgeAttr{data=$(string(a.data))}")
+end
 
 struct OSDevAttr <: Attribute
     type_::Symbol
@@ -146,9 +171,13 @@ function load_attr(hattr::Ptr{hwloc_obj_attr_u}, type_::Symbol)
     elseif type_==:Misc
         error("not implemented")
     elseif type_==:Bridge
-        return NullAttr()
+        ha = unsafe_load(convert(Ptr{hwloc_bridge_attr_s}, hattr))
+        println(ha)
+        return BridgeAttr(ha)
+        # return NullAttr()
     elseif type_==:PCI_Device
         ha = unsafe_load(convert(Ptr{hwloc_pcidev_attr_s}, hattr))
+        println(ha)
         return PCIDevAttr(ha)
     elseif type_==:OS_Device
         return NullAttr()

From 74096db9f0c435ba7199e7df4cf75170119f9eb1 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Thu, 13 Jul 2023 22:57:10 -0700
Subject: [PATCH 06/36] extract more pci data

---
 src/lowlevel_api.jl | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index eb23754..d8b5cae 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -9,7 +9,8 @@ using ..LibHwloc:
     hwloc_topology_set_type_filter, hwloc_topology_get_type_filter,
     hwloc_topology_set_all_types_filter, hwloc_topology_set_cache_types_filter,
     hwloc_topology_set_icache_types_filter, hwloc_topology_set_io_types_filter,
-    hwloc_topology_set_userdata, hwloc_topology_get_userdata
+    hwloc_topology_set_userdata, hwloc_topology_get_userdata,
+    var"##Ctag#349", var"##Ctag#350"
 
 # List of special capitalizations -- cenum_name_to_symbol will by default
 # convert the all-uppcase C enum name to lowercase (with capitalized leading
@@ -120,13 +121,28 @@ function show(io::IO, a::PCIDevAttr)
 end
 
 struct BridgeAttr <: Attribute
-    data::NTuple{40, UInt8}
+    upstream::var"##Ctag#349"
+    upstream_type::hwloc_obj_bridge_type_t
+    downstream::var"##Ctag#350"
+    downstream_type::hwloc_obj_bridge_type_t
+    depth::UInt
 end
 function BridgeAttr(ha::hwloc_bridge_attr_s)
-    return BridgeAttr(ha.data)
+    return BridgeAttr(
+        ha.upstream, ha.upstream_type,
+        ha.downstream, ha.downstream_type,
+        ha.depth
+    )
 end
 function show(io::IO, a::BridgeAttr)
-    print(io, "BridgeAttr{data=$(string(a.data))}")
+    print(
+        io,
+        "BridgeAttr{upstream=$(string(a.upstream)), "    *
+        "upstream_type=$(string(a.upstream_type)), "     *
+        "downstream=$(string(a.downstream)), "           *
+        "downstream_type=$(string(a.downstream_type)), " *
+        "}"
+    )
 end
 
 struct OSDevAttr <: Attribute
@@ -172,12 +188,9 @@ function load_attr(hattr::Ptr{hwloc_obj_attr_u}, type_::Symbol)
         error("not implemented")
     elseif type_==:Bridge
         ha = unsafe_load(convert(Ptr{hwloc_bridge_attr_s}, hattr))
-        println(ha)
         return BridgeAttr(ha)
-        # return NullAttr()
     elseif type_==:PCI_Device
         ha = unsafe_load(convert(Ptr{hwloc_pcidev_attr_s}, hattr))
-        println(ha)
         return PCIDevAttr(ha)
     elseif type_==:OS_Device
         return NullAttr()

From c95c25d336d0148ec00a53b12de941d9c9010c18 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 16 Jul 2023 21:49:03 -0700
Subject: [PATCH 07/36] read dev class id

---
 src/Hwloc.jl               |  1 +
 src/libhwloc_extensions.jl | 17 +++++++++++++++++
 src/lowlevel_api.jl        | 15 +++++++++------
 3 files changed, 27 insertions(+), 6 deletions(-)
 create mode 100644 src/libhwloc_extensions.jl

diff --git a/src/Hwloc.jl b/src/Hwloc.jl
index 9bcbc00..1255d08 100644
--- a/src/Hwloc.jl
+++ b/src/Hwloc.jl
@@ -5,6 +5,7 @@ using Statistics
 import Base: show, IteratorSize, IteratorEltype, isempty, eltype, iterate
 
 include("libhwloc.jl")
+include("libhwloc_extensions.jl")
 include("lowlevel_api.jl")
 include("highlevel_api.jl")
 
diff --git a/src/libhwloc_extensions.jl b/src/libhwloc_extensions.jl
new file mode 100644
index 0000000..bb5d5b0
--- /dev/null
+++ b/src/libhwloc_extensions.jl
@@ -0,0 +1,17 @@
+module LibHwlocExtensions
+
+using ..LibHwloc: libhwloc, Hwloc_jll
+
+using CEnum
+
+function hwloc_pci_class_string(class_id)
+    val = ccall(
+        (:hwloc_pci_class_string, libhwloc),
+        Ptr{Cchar},
+        (Cushort,),
+        class_id
+    )
+    return unsafe_string(val)
+end
+
+end
\ No newline at end of file
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index d8b5cae..6ea3c4e 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -12,6 +12,9 @@ using ..LibHwloc:
     hwloc_topology_set_userdata, hwloc_topology_get_userdata,
     var"##Ctag#349", var"##Ctag#350"
 
+using ..LibHwlocExtensions:
+    hwloc_pci_class_string
+
 # List of special capitalizations -- cenum_name_to_symbol will by default
 # convert the all-uppcase C enum name to lowercase (with capitalized leading
 # character). Any names listed here will be capitalized as stated below:
@@ -110,7 +113,7 @@ function show(io::IO, a::PCIDevAttr)
         "PCIDev(domain=$(a.domain), "      *
         "bus=$(a.bus), "                   *
         "func=$(a.func), "                 *
-        "class_id=$(a.class_id), "         *
+        "class_id=$(hwloc_pci_class_string(a.class_id)), "         *
         "vendor_id=$(a.vendor_id), "       *
         "device_id=$(a.device_id), "       *
         "subvendor_id=$(a.subvendor_id), " *
@@ -137,11 +140,10 @@ end
 function show(io::IO, a::BridgeAttr)
     print(
         io,
-        "BridgeAttr{upstream=$(string(a.upstream)), "    *
-        "upstream_type=$(string(a.upstream_type)), "     *
-        "downstream=$(string(a.downstream)), "           *
-        "downstream_type=$(string(a.downstream_type)), " *
-        "}"
+        "BridgeAttr(US=$(hwloc_pci_class_string(a.upstream.pci.class_id)), " *
+        "upstream_type=$(string(a.upstream_type)), "                         *
+        "downstream_type=$(string(a.downstream_type)) "                      *
+        ")"
     )
 end
 
@@ -260,6 +262,7 @@ function load(hobj::hwloc_obj_t)
     os_index = mod(obj.os_index, Cint)
 
     name = obj.name == C_NULL ? "" : unsafe_string(obj.name)
+    println(name)
 
     attr = load_attr(obj.attr, type_)
 

From f54ee3e518101209cc4a4990609e844d48e2a063 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Thu, 20 Jul 2023 23:15:23 -0700
Subject: [PATCH 08/36] wip on inserting process information

---
 src/highlevel_api.jl | 18 ++++++++++++++----
 src/lowlevel_api.jl  | 28 ++++++++++++++++++----------
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 8c1ed60..b947e4a 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -1,4 +1,4 @@
-using ..LibHwloc: hwloc_get_api_version
+using ..LibHwloc: hwloc_get_api_version, HWLOC_OBJ_BRIDGE_HOST
 
 
 """
@@ -21,20 +21,30 @@ Prints the topology of the given `obj` as a tree to `io`.
 """
 function print_topology(io::IO = stdout, obj::Object = gettopology(); indent = "", newline = false, prefix = "")
     t = hwloc_typeof(obj)
+
+    # println("t=$(t) name=$(obj.name)")
+
     idxstr = t in (:Package, :Core, :PU) ? "L#$(obj.logical_index) P#$(obj.os_index) " : ""
     attrstr = string(obj.attr)
 
     if t in (:L1Cache, :L2Cache, :L3Cache, :L1ICache)
         tstr = first(string(t), 2)
         attrstr = "("*_bytes2string(obj.attr.size)*")"
+    elseif t == :Bridge
+        if obj.attr.upstream_type == HWLOC_OBJ_BRIDGE_HOST
+            tstr = "HostBridge"
+        else
+            tstr = "PCIBridge"
+        end
     else
         tstr = string(t)
     end
 
     newline && print(io, "\n", indent)
-    print(io, prefix, tstr, " ",
-        idxstr,
-        attrstr, obj.mem > 0 ? "("*_bytes2string(obj.mem)*")" : "")
+    print(
+        io, prefix, tstr, " ", idxstr, attrstr,
+        obj.mem > 0 ? "("*_bytes2string(obj.mem)*")" : ""
+    )
 
     for memchild in obj.memory_children
         memstr = "("*_bytes2string(memchild.mem)*")"
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 6ea3c4e..654e3ce 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -110,15 +110,15 @@ end
 function show(io::IO, a::PCIDevAttr)
     print(
         io,
-        "PCIDev(domain=$(a.domain), "      *
-        "bus=$(a.bus), "                   *
-        "func=$(a.func), "                 *
-        "class_id=$(hwloc_pci_class_string(a.class_id)), "         *
-        "vendor_id=$(a.vendor_id), "       *
-        "device_id=$(a.device_id), "       *
-        "subvendor_id=$(a.subvendor_id), " *
-        "subdevice_id=$(a.subdevice_id), " *
-        "revision=$(a.revision), "         *
+        "PCIDev(domain=$(a.domain), "                      *
+        "bus=$(a.bus), "                                   *
+        "func=$(a.func), "                                 *
+        "class_id=$(hwloc_pci_class_string(a.class_id)), " *
+        "vendor_id=$(a.vendor_id), "                       *
+        "device_id=$(a.device_id), "                       *
+        "subvendor_id=$(a.subvendor_id), "                 *
+        "subdevice_id=$(a.subdevice_id), "                 *
+        "revision=$(a.revision), "                         *
         "linkspeed=$(a.linkspeed))"
     )
 end
@@ -262,7 +262,6 @@ function load(hobj::hwloc_obj_t)
     os_index = mod(obj.os_index, Cint)
 
     name = obj.name == C_NULL ? "" : unsafe_string(obj.name)
-    println(name)
 
     attr = load_attr(obj.attr, type_)
 
@@ -298,6 +297,15 @@ function load(hobj::hwloc_obj_t)
         end
     end
 
+    misc_children = Object[]
+    if obj.misc_arity != 0
+        misc_child = obj.misc_first_child
+        while misc_child != C_NULL
+            push!(misc_children, load(misc_child))
+            misc_child = unsafe_load(misc_child).next_sibling
+        end
+    end
+
     topo = Object(
         type_, os_index, name, attr, mem, depth, logical_index, children,
         memory_children, io_children

From 448948cc5b8c5108b47f895eabbf8740d3139da1 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 22 Jul 2023 21:32:17 -0700
Subject: [PATCH 09/36] print PCI devices properly now

---
 Project.toml         |  3 ++-
 src/highlevel_api.jl | 39 ++++++++++++++++++++++++++++++++-------
 src/lowlevel_api.jl  |  1 +
 3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/Project.toml b/Project.toml
index 21819ea..c249720 100644
--- a/Project.toml
+++ b/Project.toml
@@ -6,12 +6,13 @@ version = "3.0.0"
 [deps]
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
 Hwloc_jll = "e33a78d0-f292-5ffc-b300-72abe9b543c8"
+Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
+CEnum = "0.4"
 Hwloc_jll = "2.8"
 julia = "1.6"
-CEnum = "0.4"
 
 [extras]
 CpuId = "adafc99b-e345-5852-983c-f28acb93d879"
diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index b947e4a..9151676 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -1,5 +1,6 @@
 using ..LibHwloc: hwloc_get_api_version, HWLOC_OBJ_BRIDGE_HOST
 
+using Printf
 
 """
 Returns the API version of libhwloc.
@@ -14,12 +15,17 @@ function get_api_version()
     VersionNumber(major, minor, patch)
 end
 
+const minimal_classes = ["VGA", "NVMExp", "Network"]
+
 """
     print_topology([io::IO = stdout, obj::Object = gettopology()])
 
 Prints the topology of the given `obj` as a tree to `io`.
 """
-function print_topology(io::IO = stdout, obj::Object = gettopology(); indent = "", newline = false, prefix = "")
+function print_topology(
+        io::IO = stdout, obj::Object = gettopology();
+        indent = "", newline = false, prefix = "", minimal=true
+    )
     t = hwloc_typeof(obj)
 
     # println("t=$(t) name=$(obj.name)")
@@ -27,24 +33,43 @@ function print_topology(io::IO = stdout, obj::Object = gettopology(); indent = "
     idxstr = t in (:Package, :Core, :PU) ? "L#$(obj.logical_index) P#$(obj.os_index) " : ""
     attrstr = string(obj.attr)
 
+    # this is set to false whenever minimal == true and the PCI class_id strings
+    # don't match the minimal_classes list
+    print_device = true
+
     if t in (:L1Cache, :L2Cache, :L3Cache, :L1ICache)
         tstr = first(string(t), 2)
         attrstr = "("*_bytes2string(obj.attr.size)*")"
     elseif t == :Bridge
         if obj.attr.upstream_type == HWLOC_OBJ_BRIDGE_HOST
-            tstr = "HostBridge"
+            tstr    = "HostBridge"
+            attrstr = ""
         else
             tstr = "PCIBridge"
+            attrstr = ""
+        end
+    elseif t == :PCI_Device
+        class_string = hwloc_pci_class_string(obj.attr.class_id)
+        tstr    = "PCI"
+        attrstr = @sprintf(
+            "%s%02x:%02x.%01x",
+            Char(obj.attr.domain), obj.attr.bus, obj.attr.dev, obj.attr.func
+        ) * " ($(class_string))"
+        if minimal
+            print_device = (class_string in minimal_classes)
         end
     else
         tstr = string(t)
+        attrstr = obj.name
     end
 
-    newline && print(io, "\n", indent)
-    print(
-        io, prefix, tstr, " ", idxstr, attrstr,
-        obj.mem > 0 ? "("*_bytes2string(obj.mem)*")" : ""
-    )
+    if print_device
+        newline && print(io, "\n", indent)
+        print(
+            io, prefix, tstr, " ", idxstr, attrstr,
+            obj.mem > 0 ? "("*_bytes2string(obj.mem)*")" : ""
+        )
+    end
 
     for memchild in obj.memory_children
         memstr = "("*_bytes2string(memchild.mem)*")"
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 654e3ce..46a408d 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -112,6 +112,7 @@ function show(io::IO, a::PCIDevAttr)
         io,
         "PCIDev(domain=$(a.domain), "                      *
         "bus=$(a.bus), "                                   *
+        "dev=$(a.dev), "                                   *
         "func=$(a.func), "                                 *
         "class_id=$(hwloc_pci_class_string(a.class_id)), " *
         "vendor_id=$(a.vendor_id), "                       *

From f0aa7f8c50487a5bd352fa8315b803c6fd9a42c6 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 23 Jul 2023 16:35:14 -0700
Subject: [PATCH 10/36] get lstopo-style printing

---
 src/highlevel_api.jl | 56 ++++++++++++++++++++++++++++++++++++++------
 src/lowlevel_api.jl  | 17 ++++++++------
 2 files changed, 59 insertions(+), 14 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 9151676..fc03336 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -1,4 +1,6 @@
-using ..LibHwloc: hwloc_get_api_version, HWLOC_OBJ_BRIDGE_HOST
+using ..LibHwloc: hwloc_get_api_version, HWLOC_OBJ_BRIDGE_HOST,
+    HWLOC_OBJ_OSDEV_BLOCK, HWLOC_OBJ_OSDEV_GPU, HWLOC_OBJ_OSDEV_NETWORK,
+    HWLOC_OBJ_OSDEV_OPENFABRICS, HWLOC_OBJ_OSDEV_DMA, HWLOC_OBJ_OSDEV_COPROC
 
 using Printf
 
@@ -15,7 +17,32 @@ function get_api_version()
     VersionNumber(major, minor, patch)
 end
 
-const minimal_classes = ["VGA", "NVMExp", "Network"]
+const minimal_classes = ["VGA", "NVMExp", "Network", "Other"]
+subtype_str(obj) = obj.subtype == "" ? "" : "($(obj.subtype))"
+
+function is_visible(obj::Object; minimal=true)
+    t = hwloc_typeof(obj)
+
+    if t == :Bridge
+        for child in obj.io_children
+            if is_visible(child)
+                return true
+            end
+        end
+        return false
+    end
+
+    if t == :PCI_Device
+        class_string = hwloc_pci_class_string(obj.attr.class_id)
+        if minimal
+            return class_string in minimal_classes
+        else
+            return true
+        end
+    end
+
+    return true
+end
 
 """
     print_topology([io::IO = stdout, obj::Object = gettopology()])
@@ -28,14 +55,12 @@ function print_topology(
     )
     t = hwloc_typeof(obj)
 
-    # println("t=$(t) name=$(obj.name)")
-
     idxstr = t in (:Package, :Core, :PU) ? "L#$(obj.logical_index) P#$(obj.os_index) " : ""
     attrstr = string(obj.attr)
 
     # this is set to false whenever minimal == true and the PCI class_id strings
     # don't match the minimal_classes list
-    print_device = true
+    print_device = is_visible(obj; minimal=minimal)
 
     if t in (:L1Cache, :L2Cache, :L3Cache, :L1ICache)
         tstr = first(string(t), 2)
@@ -55,8 +80,22 @@ function print_topology(
             "%s%02x:%02x.%01x",
             Char(obj.attr.domain), obj.attr.bus, obj.attr.dev, obj.attr.func
         ) * " ($(class_string))"
-        if minimal
-            print_device = (class_string in minimal_classes)
+    elseif t == :OS_Device
+        attrstr = "\"$(obj.name)\""
+        tstr = string(t) * " " * if obj.attr.type == HWLOC_OBJ_OSDEV_BLOCK
+            "Block$(subtype_str(obj))"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_GPU
+            "GPU"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_NETWORK
+            "Net"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_OPENFABRICS
+            "OpenFabrics"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_DMA
+            "DMA"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_COPROC
+            "CoProc"
+        else
+            string(obj.attr)
         end
     else
         tstr = string(t)
@@ -69,6 +108,8 @@ function print_topology(
             io, prefix, tstr, " ", idxstr, attrstr,
             obj.mem > 0 ? "("*_bytes2string(obj.mem)*")" : ""
         )
+    else
+        return nothing
     end
 
     for memchild in obj.memory_children
@@ -89,6 +130,7 @@ function print_topology(
     for child in obj.io_children
         print_topology(io, child; indent=indent*repeat(" ", 4), newline=true)
     end
+
     return nothing
 end
 print_topology(obj::Object) = print_topology(stdout, obj)
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 46a408d..df2df55 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -9,8 +9,8 @@ using ..LibHwloc:
     hwloc_topology_set_type_filter, hwloc_topology_get_type_filter,
     hwloc_topology_set_all_types_filter, hwloc_topology_set_cache_types_filter,
     hwloc_topology_set_icache_types_filter, hwloc_topology_set_io_types_filter,
-    hwloc_topology_set_userdata, hwloc_topology_get_userdata,
-    var"##Ctag#349", var"##Ctag#350"
+    hwloc_topology_set_userdata, hwloc_topology_get_userdata, var"##Ctag#349",
+    var"##Ctag#350"
 
 using ..LibHwlocExtensions:
     hwloc_pci_class_string
@@ -149,10 +149,10 @@ function show(io::IO, a::BridgeAttr)
 end
 
 struct OSDevAttr <: Attribute
-    type_::Symbol
+    type::hwloc_obj_osdev_type_t
 end
 function show(io::IO, a::OSDevAttr)
-    print(io, "OSDev{type=$(string(a.type_))}")
+    print(io, "OSDev{type=$(string(a.type))}")
 end
 
 struct DieAttr <: Attribute
@@ -196,7 +196,8 @@ function load_attr(hattr::Ptr{hwloc_obj_attr_u}, type_::Symbol)
         ha = unsafe_load(convert(Ptr{hwloc_pcidev_attr_s}, hattr))
         return PCIDevAttr(ha)
     elseif type_==:OS_Device
-        return NullAttr()
+        ha = unsafe_load(convert(Ptr{hwloc_obj_osdev_type_t}, hattr))
+        return OSDevAttr(ha)
     elseif type_==:Die
         ha = unsafe_load(convert(Ptr{hwloc_cache_attr_s}, hattr))
         return DieAttr(ha.depth)
@@ -210,6 +211,7 @@ end
 
 struct Object
     type_::Symbol
+    subtype::String
     os_index::Int
     name::String
     attr::Attribute
@@ -259,6 +261,7 @@ function load(hobj::hwloc_obj_t)
 
     @assert Integer(obj.type)>=0 && Integer(obj.type)<length(obj_types)
     type_ = obj_types[obj.type+1]
+    subtype = obj.subtype == C_NULL ? "" : unsafe_string(obj.subtype)
 
     os_index = mod(obj.os_index, Cint)
 
@@ -308,8 +311,8 @@ function load(hobj::hwloc_obj_t)
     end
 
     topo = Object(
-        type_, os_index, name, attr, mem, depth, logical_index, children,
-        memory_children, io_children
+        type_, subtype, os_index, name, attr, mem, depth, logical_index,
+        children, memory_children, io_children
     )
     return topo
 end

From c192376ede4f4bec4fd4eb18f334a7c1ba2f375e Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 23 Jul 2023 17:02:25 -0700
Subject: [PATCH 11/36] add coproc subtype

---
 src/highlevel_api.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index fc03336..2c50a6e 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -82,7 +82,7 @@ function print_topology(
         ) * " ($(class_string))"
     elseif t == :OS_Device
         attrstr = "\"$(obj.name)\""
-        tstr = string(t) * " " * if obj.attr.type == HWLOC_OBJ_OSDEV_BLOCK
+        tstr = if obj.attr.type == HWLOC_OBJ_OSDEV_BLOCK
             "Block$(subtype_str(obj))"
         elseif obj.attr.type == HWLOC_OBJ_OSDEV_GPU
             "GPU"
@@ -93,7 +93,7 @@ function print_topology(
         elseif obj.attr.type == HWLOC_OBJ_OSDEV_DMA
             "DMA"
         elseif obj.attr.type == HWLOC_OBJ_OSDEV_COPROC
-            "CoProc"
+            "CoProc$(subtype_str(obj))"
         else
             string(obj.attr)
         end

From 7b10523e18428c90ebe36482b0f7e211b7f632e4 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <jpblaschke@lbl.gov>
Date: Sun, 23 Jul 2023 20:10:50 -0700
Subject: [PATCH 12/36] update list of minimal device types

---
 Project.toml         | 2 +-
 src/highlevel_api.jl | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Project.toml b/Project.toml
index c249720..c76d7d9 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Hwloc"
 uuid = "0e44f5e4-bd66-52a0-8798-143a42290a1d"
 authors = ["Erik Schnetter <schnetter@gmail.com>"]
-version = "3.0.0"
+version = "3.1.0"
 
 [deps]
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 2c50a6e..7d43a3b 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -17,7 +17,7 @@ function get_api_version()
     VersionNumber(major, minor, patch)
 end
 
-const minimal_classes = ["VGA", "NVMExp", "Network", "Other"]
+const minimal_classes = ["VGA", "NVMExp", "Network", "Ethernet", "Other"]
 subtype_str(obj) = obj.subtype == "" ? "" : "($(obj.subtype))"
 
 function is_visible(obj::Object; minimal=true)
@@ -33,8 +33,8 @@ function is_visible(obj::Object; minimal=true)
     end
 
     if t == :PCI_Device
-        class_string = hwloc_pci_class_string(obj.attr.class_id)
         if minimal
+            class_string = hwloc_pci_class_string(obj.attr.class_id)
             return class_string in minimal_classes
         else
             return true

From 3152c286e8e1ff1f67c97655f4a5bf3e9c429315 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <jpblaschke@lbl.gov>
Date: Sun, 23 Jul 2023 20:18:39 -0700
Subject: [PATCH 13/36] add more minimal devices

---
 src/highlevel_api.jl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 7d43a3b..c180052 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -17,7 +17,9 @@ function get_api_version()
     VersionNumber(major, minor, patch)
 end
 
-const minimal_classes = ["VGA", "NVMExp", "Network", "Ethernet", "Other"]
+const minimal_classes = [
+    "VGA", "NVMExp", "SATA", "Network", "Ethernet", "InfiniBand", "3D", "Other"
+]
 subtype_str(obj) = obj.subtype == "" ? "" : "($(obj.subtype))"
 
 function is_visible(obj::Object; minimal=true)

From 5fb034c080a3b568c524d338e9e72285925bd185 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <jpblaschke@lbl.gov>
Date: Mon, 24 Jul 2023 17:33:00 -0700
Subject: [PATCH 14/36] start working on trees

---
 Project.toml        |  3 ++-
 src/Hwloc.jl        |  2 ++
 src/lowlevel_api.jl | 18 ++++++++++--------
 src/tree.jl         | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 48 insertions(+), 9 deletions(-)
 create mode 100644 src/tree.jl

diff --git a/Project.toml b/Project.toml
index c76d7d9..017d43c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,9 +1,10 @@
 name = "Hwloc"
 uuid = "0e44f5e4-bd66-52a0-8798-143a42290a1d"
 authors = ["Erik Schnetter <schnetter@gmail.com>"]
-version = "3.1.0"
+version = "3.1.1"
 
 [deps]
+AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
 Hwloc_jll = "e33a78d0-f292-5ffc-b300-72abe9b543c8"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
diff --git a/src/Hwloc.jl b/src/Hwloc.jl
index 1255d08..aff37da 100644
--- a/src/Hwloc.jl
+++ b/src/Hwloc.jl
@@ -8,11 +8,13 @@ include("libhwloc.jl")
 include("libhwloc_extensions.jl")
 include("lowlevel_api.jl")
 include("highlevel_api.jl")
+include("tree.jl")
 
 export topology, gettopology, topology_info, getinfo, print_topology, topology_graphical
 export num_physical_cores, num_virtual_cores, num_packages, num_numa_nodes
 export cachesize, cachelinesize
 export hwloc_typeof, hwloc_isa, collectobjects
+export HwlocTreeNode
 
 const machine_topology = Ref{Object}()
 
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index df2df55..e33072c 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -301,14 +301,16 @@ function load(hobj::hwloc_obj_t)
         end
     end
 
-    misc_children = Object[]
-    if obj.misc_arity != 0
-        misc_child = obj.misc_first_child
-        while misc_child != C_NULL
-            push!(misc_children, load(misc_child))
-            misc_child = unsafe_load(misc_child).next_sibling
-        end
-    end
+    # not needed for now -- unless we want to start putting things (like
+    # processes into the Hwloc tree)
+    # misc_children = Object[]
+    # if obj.misc_arity != 0
+    #     misc_child = obj.misc_first_child
+    #     while misc_child != C_NULL
+    #         push!(misc_children, load(misc_child))
+    #         misc_child = unsafe_load(misc_child).next_sibling
+    #     end
+    # end
 
     topo = Object(
         type_, subtype, os_index, name, attr, mem, depth, logical_index,
diff --git a/src/tree.jl b/src/tree.jl
new file mode 100644
index 0000000..27df695
--- /dev/null
+++ b/src/tree.jl
@@ -0,0 +1,34 @@
+import AbstractTrees
+
+mutable struct HwlocTreeNode
+    object::Object
+    type::Symbol
+
+    parent::Union{Nothing, HwlocTreeNode}
+    children::Vector{HwlocTreeNode}
+    memory_children::Vector{HwlocTreeNode}
+    io_children::Vector{HwlocTreeNode}
+
+    function HwlocTreeNode(obj::Object; parent=nothing, type=nothing)
+        this = new(obj, obj.type_, parent)
+
+        this.children = HwlocTreeNode.(obj.children; parent=this)
+        this.memory_children = HwlocTreeNode.(obj.memory_children; parent=this)
+        this.io_children = HwlocTreeNode.(obj.io_children; parent=this)
+        
+        return this
+    end
+end
+
+function AbstractTrees.children(node::HwlocTreeNode)
+    tuple(node.children..., node.memory_children..., node.io_children...)
+end
+
+AbstractTrees.nodevalue(n::HwlocTreeNode) = n.object
+
+AbstractTrees.ParentLinks(::Type{<:HwlocTreeNode}) = StoredParents()
+
+AbstractTrees.parent(n::HwlocTreeNode) = n.parent
+
+AbstractTrees.NodeType(::Type{<:HwlocTreeNode}) where {T} = HasNodeType()
+AbstractTrees.nodetype(::Type{<:HwlocTreeNode}) where {T} = HwlocTreeNode
\ No newline at end of file

From 9b688815849cf02f6d796cd710badb57e17ea4c0 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <jpblaschke@lbl.gov>
Date: Mon, 24 Jul 2023 17:35:30 -0700
Subject: [PATCH 15/36] fix

---
 src/tree.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tree.jl b/src/tree.jl
index 27df695..2778149 100644
--- a/src/tree.jl
+++ b/src/tree.jl
@@ -30,5 +30,5 @@ AbstractTrees.ParentLinks(::Type{<:HwlocTreeNode}) = StoredParents()
 
 AbstractTrees.parent(n::HwlocTreeNode) = n.parent
 
-AbstractTrees.NodeType(::Type{<:HwlocTreeNode}) where {T} = HasNodeType()
-AbstractTrees.nodetype(::Type{<:HwlocTreeNode}) where {T} = HwlocTreeNode
\ No newline at end of file
+AbstractTrees.NodeType(::Type{<:HwlocTreeNode}) = HasNodeType()
+AbstractTrees.nodetype(::Type{<:HwlocTreeNode}) = HwlocTreeNode
\ No newline at end of file

From 8d5d31c6011ed08ba6de2b04ceaf84664f39ed68 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <jpblaschke@lbl.gov>
Date: Wed, 26 Jul 2023 12:02:51 -0700
Subject: [PATCH 16/36] add taggable trees

---
 src/tree.jl | 77 +++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 63 insertions(+), 14 deletions(-)

diff --git a/src/tree.jl b/src/tree.jl
index 2778149..ea78c62 100644
--- a/src/tree.jl
+++ b/src/tree.jl
@@ -1,21 +1,22 @@
 import AbstractTrees
 
-mutable struct HwlocTreeNode
+mutable struct HwlocTreeNode{T}
     object::Object
     type::Symbol
+    tag::Union{Nothing, T}
 
-    parent::Union{Nothing, HwlocTreeNode}
-    children::Vector{HwlocTreeNode}
-    memory_children::Vector{HwlocTreeNode}
-    io_children::Vector{HwlocTreeNode}
+    parent::Union{Nothing, HwlocTreeNode{T}}
+    children::Vector{HwlocTreeNode{T}}
+    memory_children::Vector{HwlocTreeNode{T}}
+    io_children::Vector{HwlocTreeNode{T}}
 
-    function HwlocTreeNode(obj::Object; parent=nothing, type=nothing)
-        this = new(obj, obj.type_, parent)
+    function HwlocTreeNode{T}(obj::Object; parent=nothing, type=nothing) where {T}
+        this = new{T}(obj, obj.type_, nothing, parent)
+
+        this.children = HwlocTreeNode{T}.(obj.children; parent=this)
+        this.memory_children = HwlocTreeNode{T}.(obj.memory_children; parent=this)
+        this.io_children = HwlocTreeNode{T}.(obj.io_children; parent=this)
 
-        this.children = HwlocTreeNode.(obj.children; parent=this)
-        this.memory_children = HwlocTreeNode.(obj.memory_children; parent=this)
-        this.io_children = HwlocTreeNode.(obj.io_children; parent=this)
-        
         return this
     end
 end
@@ -26,9 +27,57 @@ end
 
 AbstractTrees.nodevalue(n::HwlocTreeNode) = n.object
 
-AbstractTrees.ParentLinks(::Type{<:HwlocTreeNode}) = StoredParents()
+AbstractTrees.ParentLinks(::Type{<:HwlocTreeNode}) = AbstractTrees.StoredParents()
 
 AbstractTrees.parent(n::HwlocTreeNode) = n.parent
 
-AbstractTrees.NodeType(::Type{<:HwlocTreeNode}) = HasNodeType()
-AbstractTrees.nodetype(::Type{<:HwlocTreeNode}) = HwlocTreeNode
\ No newline at end of file
+AbstractTrees.NodeType(::Type{<:HwlocTreeNode{T}}) where {T} = AbstractTrees.HasNodeType()
+AbstractTrees.nodetype(::Type{<:HwlocTreeNode{T}}) where {T} = HwlocTreeNode{T}
+
+function AbstractTrees.printnode(io::IO, node::HwlocTreeNode)
+    obj = AbstractTrees.nodevalue(node)
+    label = string(obj)
+    if node.type in (:Package, :Core, :PU)
+        label = label * " [L#$(obj.logical_index) P#$(obj.os_index)]"
+    elseif node.type == :Bridge
+        if obj.attr.upstream_type == HWLOC_OBJ_BRIDGE_HOST
+            label = label * " [HostBridge]"
+        else
+            label = label * " [PCIBridge]"
+        end
+    elseif node.type == :PCI_Device
+        class_string = hwloc_pci_class_string(obj.attr.class_id)
+        label = label * " [" * @sprintf(
+            "%s%02x:%02x.%01x",
+            Char(obj.attr.domain), obj.attr.bus, obj.attr.dev, obj.attr.func
+        ) * " ($(class_string))]"
+    elseif node.type == :OS_Device
+        label = label * " [" * if obj.attr.type == HWLOC_OBJ_OSDEV_BLOCK
+            "Block$(subtype_str(obj))"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_GPU
+            "GPU"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_NETWORK
+            "Net"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_OPENFABRICS
+            "OpenFabrics"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_DMA
+            "DMA"
+        elseif obj.attr.type == HWLOC_OBJ_OSDEV_COPROC
+            "CoProc$(subtype_str(obj))"
+        else
+            string(obj.attr)
+        end * " \"$(obj.name)\"]"
+    end
+    print(io, label)
+end
+
+get_nodes(tree_node, type) = filter(
+    x->x.type == type,
+    collect(AbstractTrees.PreOrderDFS(tree_node))
+)
+
+function tag_subtree!(tree_node, val)
+    for n in collect(AbstractTrees.PreOrderDFS(tree_node))
+        n.tag = val
+    end
+end

From c8923d28fdd9d5174239986b0d419f44a10af5e9 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 30 Dec 2023 21:31:30 -0800
Subject: [PATCH 17/36] update Pkg compat

---
 Project.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Project.toml b/Project.toml
index c76d7d9..32cd262 100644
--- a/Project.toml
+++ b/Project.toml
@@ -10,9 +10,9 @@ Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
-CEnum = "0.4"
+CEnum = "≥ 0.4"
 Hwloc_jll = "2.8"
-julia = "1.6"
+julia = "≥ 1.6"
 
 [extras]
 CpuId = "adafc99b-e345-5852-983c-f28acb93d879"

From 0685838e430cbdea2c7fe17d3c4788c5294de5e5 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 30 Dec 2023 21:49:08 -0800
Subject: [PATCH 18/36] add more control whether or not to print I/O devices

---
 src/highlevel_api.jl | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index c180052..98a09d4 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -143,10 +143,10 @@ Returns the top-level system topology `Object`.
 On first call, it loads the topology by querying libhwloc and caches the result.
 Pass `reload=true` in order to force reload.
 """
-function gettopology(htopo=nothing; reload=false)
+function gettopology(htopo=nothing; reload=false, get_io=true)
     if reload || (!isassigned(machine_topology))
         if isnothing(htopo)
-            htopo=topology_init()
+            htopo=topology_init(;get_io=get_io)
         end
         machine_topology[] = topology_load(htopo)
     end
@@ -391,7 +391,11 @@ The quality of the result might depend on the used terminal and might vary betwe
 
 **Note:** The specific visualization may change between minor versions.
 """
-function topology_graphical()
-    run(`$(lstopo_no_graphics()) --no-legend --of txt`)
+function topology_graphical(;get_io=true)
+    if get_io
+        run(`$(lstopo_no_graphics()) --no-legend --of txt`)
+    else
+        run(`$(lstopo_no_graphics()) --no-io --no-legend --of txt`)
+    end
     return nothing
 end

From 8fc464f8852d3b7dacd663cfb6798083a3e3bc76 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 30 Dec 2023 21:59:38 -0800
Subject: [PATCH 19/36] Update docs

---
 src/highlevel_api.jl | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 98a09d4..9102f4b 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -47,9 +47,17 @@ function is_visible(obj::Object; minimal=true)
 end
 
 """
-    print_topology([io::IO = stdout, obj::Object = gettopology()])
+    print_topology(
+        io::IO = stdout, obj::Object = gettopology();
+        indent = "", newline = false, prefix = "", minimal=true
+    )
+
+Prints the topology of the given `obj` as a tree to `io`. 
 
-Prints the topology of the given `obj` as a tree to `io`.
+**Note:** some systems have a great deal of extra PCI devices (think USB
+bridges, and the many many device classes on custom systems like HPC clusters).
+In order to mimmic the behaviour of the `lstopo` command, we ommit these devices
+unless `minimal=false`.
 """
 function print_topology(
         io::IO = stdout, obj::Object = gettopology();

From 694e62960d8d2f04962981bc3ce89e3d84f23480 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 30 Dec 2023 22:04:10 -0800
Subject: [PATCH 20/36] fix how settings are filtered through

---
 src/highlevel_api.jl | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 9102f4b..fb0a34a 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -49,7 +49,7 @@ end
 """
     print_topology(
         io::IO = stdout, obj::Object = gettopology();
-        indent = "", newline = false, prefix = "", minimal=true
+        indent = "", newline = true, prefix = "", minimal=true
     )
 
 Prints the topology of the given `obj` as a tree to `io`. 
@@ -61,7 +61,7 @@ unless `minimal=false`.
 """
 function print_topology(
         io::IO = stdout, obj::Object = gettopology();
-        indent = "", newline = false, prefix = "", minimal=true
+        indent = "", newline = true, prefix = "", minimal=true
     )
     t = hwloc_typeof(obj)
 
@@ -131,14 +131,23 @@ function print_topology(
     for child in obj.children
         no_newline = length(obj.children)==1 && t in (:L3Cache, :L2Cache, :L1Cache)
         if no_newline
-            print_topology(io, child; indent = indent, newline=false, prefix = " + ", )
+            print_topology(
+                io, child;
+                indent = indent, newline=newline, prefix = " + ", minimal=minimal
+            )
         else
-            print_topology(io, child; indent = indent*repeat(" ", 4), newline=true)
+            print_topology(
+                io, child;
+                indent = indent*repeat(" ", 4), newline=newline, minimal=minimal
+            )
         end
     end
 
     for child in obj.io_children
-        print_topology(io, child; indent=indent*repeat(" ", 4), newline=true)
+        print_topology(
+            io, child;
+            indent=indent*repeat(" ", 4), newline=newline, minimal=minimal
+        )
     end
 
     return nothing

From 1d8e48c0b1e5c8d88aa8dfe733a753985d496b3b Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 30 Dec 2023 22:11:39 -0800
Subject: [PATCH 21/36] remove unnecessary import

---
 src/libhwloc_extensions.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libhwloc_extensions.jl b/src/libhwloc_extensions.jl
index bb5d5b0..9a9984a 100644
--- a/src/libhwloc_extensions.jl
+++ b/src/libhwloc_extensions.jl
@@ -1,6 +1,6 @@
 module LibHwlocExtensions
 
-using ..LibHwloc: libhwloc, Hwloc_jll
+using ..LibHwloc: libhwloc
 
 using CEnum
 

From 22ad3188f087c3dee2dc77104ecec6b7234e2223 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 09:12:13 -0800
Subject: [PATCH 22/36] try unsafe_wrap instead of convert->copyto

---
 src/lowlevel_api.jl | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index df2df55..8a056a8 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -277,11 +277,10 @@ function load(hobj::hwloc_obj_t)
 
     # topo.os_level = obj.os_level
 
-    obj_children = Vector{hwloc_obj_t}(UndefInitializer(), obj.arity)
-    obj_children_r = Base.unsafe_convert(Ptr{hwloc_obj_t}, obj_children)
-    unsafe_copyto!(obj_children_r, obj.children, obj.arity)
-
-    children = Object[load(child) for child in obj_children]
+    children = Object[
+        load(child)
+        for child in unsafe_wrap(Vector{hwloc_obj_t}, obj.children, obj.arity)
+    ]
 
     memory_children = Object[]
     if obj.memory_arity != 0

From 80c8e50b58d61ac228058a0c9f44403a46d7b41e Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 13:09:57 -0800
Subject: [PATCH 23/36] make abstract tree interface an extension

---
 Project.toml                     | 14 ++++++++++++--
 src/tree.jl => ext/HwlocTrees.jl | 12 ++++++++++--
 src/Hwloc.jl                     |  2 --
 3 files changed, 22 insertions(+), 6 deletions(-)
 rename src/tree.jl => ext/HwlocTrees.jl (91%)

diff --git a/Project.toml b/Project.toml
index 017d43c..4f49935 100644
--- a/Project.toml
+++ b/Project.toml
@@ -4,20 +4,30 @@ authors = ["Erik Schnetter <schnetter@gmail.com>"]
 version = "3.1.1"
 
 [deps]
-AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
 Hwloc_jll = "e33a78d0-f292-5ffc-b300-72abe9b543c8"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
+[weakdeps]
+AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
+
 [compat]
 CEnum = "0.4"
 Hwloc_jll = "2.8"
 julia = "1.6"
+AbstractTrees = "0.4.4"
 
 [extras]
 CpuId = "adafc99b-e345-5852-983c-f28acb93d879"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
+
+[extensions]
+# * name of extension to the left
+# * extension dependencies required to load the extension to the right
+# * use a list for multiple extension dependencies
+HwlocTrees = "AbstractTrees"
 
 [targets]
-test = ["Test", "CpuId"]
+test = ["Test", "CpuId", "AbstractTrees"]
diff --git a/src/tree.jl b/ext/HwlocTrees.jl
similarity index 91%
rename from src/tree.jl
rename to ext/HwlocTrees.jl
index ea78c62..be5b22a 100644
--- a/src/tree.jl
+++ b/ext/HwlocTrees.jl
@@ -1,7 +1,10 @@
+module HwlocTrees
+
+using Hwloc, Printf
 import AbstractTrees
 
 mutable struct HwlocTreeNode{T}
-    object::Object
+    object::Hwloc.Object
     type::Symbol
     tag::Union{Nothing, T}
 
@@ -10,7 +13,7 @@ mutable struct HwlocTreeNode{T}
     memory_children::Vector{HwlocTreeNode{T}}
     io_children::Vector{HwlocTreeNode{T}}
 
-    function HwlocTreeNode{T}(obj::Object; parent=nothing, type=nothing) where {T}
+    function HwlocTreeNode{T}(obj::Hwloc.Object; parent=nothing, type=nothing) where {T}
         this = new{T}(obj, obj.type_, nothing, parent)
 
         this.children = HwlocTreeNode{T}.(obj.children; parent=this)
@@ -21,6 +24,10 @@ mutable struct HwlocTreeNode{T}
     end
 end
 
+function AbstractTrees.children(node::Hwloc.Object)
+    HwlocTreeNode{UInt8}(node)
+end
+
 function AbstractTrees.children(node::HwlocTreeNode)
     tuple(node.children..., node.memory_children..., node.io_children...)
 end
@@ -81,3 +88,4 @@ function tag_subtree!(tree_node, val)
         n.tag = val
     end
 end
+end
\ No newline at end of file
diff --git a/src/Hwloc.jl b/src/Hwloc.jl
index aff37da..1255d08 100644
--- a/src/Hwloc.jl
+++ b/src/Hwloc.jl
@@ -8,13 +8,11 @@ include("libhwloc.jl")
 include("libhwloc_extensions.jl")
 include("lowlevel_api.jl")
 include("highlevel_api.jl")
-include("tree.jl")
 
 export topology, gettopology, topology_info, getinfo, print_topology, topology_graphical
 export num_physical_cores, num_virtual_cores, num_packages, num_numa_nodes
 export cachesize, cachelinesize
 export hwloc_typeof, hwloc_isa, collectobjects
-export HwlocTreeNode
 
 const machine_topology = Ref{Object}()
 

From 0236046619dacecd7da8504ea56c59307c49dcd5 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 13:19:52 -0800
Subject: [PATCH 24/36] get extension fully working

---
 ext/HwlocTrees.jl | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/ext/HwlocTrees.jl b/ext/HwlocTrees.jl
index be5b22a..3e02f7c 100644
--- a/ext/HwlocTrees.jl
+++ b/ext/HwlocTrees.jl
@@ -47,29 +47,29 @@ function AbstractTrees.printnode(io::IO, node::HwlocTreeNode)
     if node.type in (:Package, :Core, :PU)
         label = label * " [L#$(obj.logical_index) P#$(obj.os_index)]"
     elseif node.type == :Bridge
-        if obj.attr.upstream_type == HWLOC_OBJ_BRIDGE_HOST
+        if obj.attr.upstream_type == Hwloc.LibHwloc.HWLOC_OBJ_BRIDGE_HOST
             label = label * " [HostBridge]"
         else
             label = label * " [PCIBridge]"
         end
     elseif node.type == :PCI_Device
-        class_string = hwloc_pci_class_string(obj.attr.class_id)
+        class_string = Hwloc.LibHwlocExtensions.hwloc_pci_class_string(obj.attr.class_id)
         label = label * " [" * @sprintf(
             "%s%02x:%02x.%01x",
             Char(obj.attr.domain), obj.attr.bus, obj.attr.dev, obj.attr.func
         ) * " ($(class_string))]"
     elseif node.type == :OS_Device
-        label = label * " [" * if obj.attr.type == HWLOC_OBJ_OSDEV_BLOCK
-            "Block$(subtype_str(obj))"
-        elseif obj.attr.type == HWLOC_OBJ_OSDEV_GPU
+        label = label * " [" * if obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_BLOCK
+            "Block$(Hwloc.subtype_str(obj))"
+        elseif obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_GPU
             "GPU"
-        elseif obj.attr.type == HWLOC_OBJ_OSDEV_NETWORK
+        elseif obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_NETWORK
             "Net"
-        elseif obj.attr.type == HWLOC_OBJ_OSDEV_OPENFABRICS
+        elseif obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_OPENFABRICS
             "OpenFabrics"
-        elseif obj.attr.type == HWLOC_OBJ_OSDEV_DMA
+        elseif obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_DMA
             "DMA"
-        elseif obj.attr.type == HWLOC_OBJ_OSDEV_COPROC
+        elseif obj.attr.type == Hwloc.LibHwloc.HWLOC_OBJ_OSDEV_COPROC
             "CoProc$(subtype_str(obj))"
         else
             string(obj.attr)

From 9f0253bfbb4a2fe2ff23bdbd47132e90182f8e9c Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 13:39:53 -0800
Subject: [PATCH 25/36] add tests

---
 test/runtests.jl | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/test/runtests.jl b/test/runtests.jl
index 241a0e4..54b5824 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -119,4 +119,11 @@ import CpuId
             @test first(collectobjects(:NUMANode)).mem > 0
         end
     end
+
+    @testset "AbstractTrees interface" begin
+        using AbstractTrees
+        t = gettopology()
+        # check that `children(gettopology)` returns the root of the HwlocTree
+        @test children(t).type == :Machine
+    end
 end

From 7382bf4992c3bb8679898fc26b8d55d068074f0b Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 15:44:53 -0800
Subject: [PATCH 26/36] update readme

---
 README.md           | 161 ++++++++++++++++++++++++++++++++++----------
 src/lowlevel_api.jl |   8 ++-
 2 files changed, 133 insertions(+), 36 deletions(-)

diff --git a/README.md b/README.md
index 69aeb33..6e038e1 100644
--- a/README.md
+++ b/README.md
@@ -24,28 +24,45 @@ On my laptop this gives the following output:
 julia> using Hwloc
 
 julia> topology()
-Machine (16.0 GB)
-    Package L#0 P#0 (16.0 GB)
-        NUMANode (16.0 GB)
+
+Machine (31.05 GB)
+    Package L#0 P#0 (31.05 GB)
+        NUMANode (31.05 GB)
         L3 (12.0 MB)
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#0 P#0 
+            L2 (1.25 MB)
+             + L1 (48.0 kB)
+             + Core L#0 P#0 
                 PU L#0 P#0 
-                PU L#1 P#1 
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#1 P#1 
-                PU L#2 P#2 
-                PU L#3 P#3 
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#2 P#2 
-                PU L#4 P#4 
-                PU L#5 P#5 
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#3 P#3 
-                PU L#6 P#6 
+                PU L#1 P#4 
+            L2 (1.25 MB)
+             + L1 (48.0 kB)
+             + Core L#1 P#1 
+                PU L#2 P#1 
+                PU L#3 P#5 
+            L2 (1.25 MB)
+             + L1 (48.0 kB)
+             + Core L#2 P#2 
+                PU L#4 P#2 
+                PU L#5 P#6 
+            L2 (1.25 MB)
+             + L1 (48.0 kB)
+             + Core L#3 P#3 
+                PU L#6 P#3 
                 PU L#7 P#7 
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#4 P#4 
-                PU L#8 P#8 
-                PU L#9 P#9 
-            L2 (256.0 kB) + L1 (32.0 kB) + Core L#5 P#5 
-                PU L#10 P#10 
-                PU L#11 P#11
+    HostBridge 
+        PCI 00:02.0 (VGA)
+            GPU "renderD128"
+            GPU "card0"
+        PCIBridge 
+            PCI 01:00.0 (NVMExp)
+                Block(Disk) "nvme0n1"
+        PCIBridge 
+            PCI 72:00.0 (Network)
+                Net "wlp114s0"
+        PCIBridge 
+            PCI 73:00.0 (Other)
+                Block "mmcblk0"
+
 ```
 
 Often, one is only interested in a summary of this topology.
@@ -53,14 +70,14 @@ The function `topology_info()` provides such a compact description, which is loo
 
 ```julia
 julia> topology_info()
-Machine: 1 (16.0 GB)
- Package: 1 (16.0 GB)
-  NUMANode: 1 (16.0 GB)
+Machine: 1 (31.05 GB)
+ Package: 1 (31.05 GB)
+  NUMANode: 1 (31.05 GB)
    L3Cache: 1 (12.0 MB)
-    L2Cache: 6 (256.0 KB)
-     L1Cache: 6 (32.0 KB)
-      Core: 6
-       PU: 12
+    L2Cache: 4 (1.25 MB)
+     L1Cache: 4 (48.0 kB)
+      Core: 4
+       PU: 8
 ```
 
 If you prefer a more verbose graphical visualization you may consider using `topology_graphical()`:
@@ -95,14 +112,14 @@ One may also use `getinfo()` to programmatically access some of the output of `t
 
 ```julia
 julia> getinfo()
-Dict{Symbol,Int64} with 8 entries:
-  :L2Cache  => 6
+Dict{Symbol, Int64} with 8 entries:
+  :L2Cache  => 4
   :NUMANode => 1
-  :Core     => 6
+  :Core     => 4
   :Package  => 1
-  :L1Cache  => 6
+  :L1Cache  => 4
   :Machine  => 1
-  :PU       => 12
+  :PU       => 8
   :L3Cache  => 1
 ```
 
@@ -190,10 +207,84 @@ julia> collectobjects(:PU, l2cache)
  Hwloc.Object: PU
 ```
 
-### Manual topology query
+### Manual topology query and caching
 
 On the first call of `gettopology()`, Hwloc.jl examines the current machine's
 hardware topology and caches the result in `Hwloc.machine_topology`.
-To manually query the system topology one may use `Hwloc.topology_load`
-which directly `ccall`s into `libhwloc` and directly returns the
-resulting `Hwloc.Object`.
+
+To query the system the system topology again -- i.e. not using the cached
+`Hwloc.Object` representing the entire machine -- simply pass the `reload=true` (`false` by default) kwarg:
+
+```julia
+julia> topo = gettopology(;reload=true)
+Hwloc.Object: Machine
+```
+
+### Do not include I/O devices in topology object
+
+You may prefer not to include I/O devices in you Hwloc tree, then we recommend
+passing the `get_io=false` (`true` by default) kwarg, in addition to `reload`
+(cf. above):
+
+```julia
+julia> topo = gettopology(;reload=true, get_io=false)
+Hwloc.Object: Machine
+
+julia> topology(topo)
+Machine (31.05 GB)
+    Package L#0 P#0 (31.05 GB)
+        NUMANode (31.05 GB)
+        L3 (12.0 MB)
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#0 P#0 
+                PU L#0 P#0 
+                PU L#1 P#4 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#1 P#1 
+                PU L#2 P#1 
+                PU L#3 P#5 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#2 P#2 
+                PU L#4 P#2 
+                PU L#5 P#6 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#3 P#3 
+                PU L#6 P#3 
+                PU L#7 P#7 
+```
+(note: to avoid caching by eccident, we recommend passing `reload=true` to
+`gettopology`)
+
+### Low-level API for accessing the underlying topology object.
+
+**Warning:** As discussed earlier, `Hwloc.jl` makes heavy use of caching in the
+high-level API. Using the low-level and high-level APIs together can result in
+cached values being used by accident! We therefore recommend that the high-level
+`gettopology` funcion is used, where caching is controlled via the `reload`
+kwarg.
+
+Under the hood, `gettopology` uses `Hwloc.topology_init` and
+`Hwloc.topology_load` to directly `ccall` into `libhwloc`. `Hwloc.topology_init`
+is reponsible for creating a low-level `LibHwloc.hwloc_topology` object.
+`Hwloc.topology_load` wraps this a `Hwloc.Object` Julia object.
+
+**Note:** `Hwloc.topology_load` is destructive to the `LibHwloc.hwloc_topology`
+object:
+
+```julia
+julia> htopo = Hwloc.topology_init()
+Ptr{Hwloc.LibHwloc.hwloc_topology} @0x000000000883cf60
+
+julia> topo = Hwloc.topology_load(htopo)
+Hwloc.Object: Machine
+
+julia> topo = Hwloc.topology_load(htopo)
+ERROR: AssertionError: ierr == 0
+Stacktrace:
+ [1] topology_load(htopo::Ptr{Hwloc.LibHwloc.hwloc_topology})
+   @ Hwloc ~/.julia/dev/Hwloc/src/lowlevel_api.jl:347
+ [2] top-level scope
+   @ REPL[78]:1
+```
+
+This is because `LibHwloc.hwloc_topology` are not garbage-collected (a call to
+`Hwloc.topology_init`, without a later call to `Hwloc.hwloc_topology_destroy`
+will leak memory). This is why `Hwloc.topology_load` calls
+`Hwloc.hwloc_topology_destroy` after creating the `Hwloc.Object` Julia object
+(which is garbage collected!).
\ No newline at end of file
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 8a056a8..8140654 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -317,6 +317,12 @@ function load(hobj::hwloc_obj_t)
 end
 
 
+"""
+    topology_init(;get_io=true)
+
+Init underlying Hwloc objec, and set the type filter to
+HWLOC_TYPE_FILTER_KEEP_ALL if `get_io==true`
+"""
 function topology_init(;get_io=true)
     r_htopo = Ref{hwloc_topology_t}()
     hwloc_topology_init(r_htopo)
@@ -356,4 +362,4 @@ function topology_load(htopo=topology_init())
     hwloc_topology_destroy(htopo)
 
     return topo
-end
+end
\ No newline at end of file

From 372fc6af8faefd62319f0c7d53dfe0557675c8b4 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 15:53:42 -0800
Subject: [PATCH 27/36] compatibility with older versions of Julia

---
 Project.toml | 1 +
 src/Hwloc.jl | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/Project.toml b/Project.toml
index 6eddd9d..61b5e0f 100644
--- a/Project.toml
+++ b/Project.toml
@@ -8,6 +8,7 @@ CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
 Hwloc_jll = "e33a78d0-f292-5ffc-b300-72abe9b543c8"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
+AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 
 [weakdeps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
diff --git a/src/Hwloc.jl b/src/Hwloc.jl
index 1255d08..6911f5e 100644
--- a/src/Hwloc.jl
+++ b/src/Hwloc.jl
@@ -16,4 +16,9 @@ export hwloc_typeof, hwloc_isa, collectobjects
 
 const machine_topology = Ref{Object}()
 
+# Compatibility with older Julia versions + module extensions:
+if !isdefined(Base, :get_extension)
+    include(joinpath("..", "ext", "HwlocTrees.jl"))
+end
+
 end

From 3e020d958b992f94e06a2c8f4770c4e9065b7bb9 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sun, 31 Dec 2023 16:18:22 -0800
Subject: [PATCH 28/36] update readme

---
 README.md | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 6e038e1..525d85e 100644
--- a/README.md
+++ b/README.md
@@ -123,7 +123,6 @@ Dict{Symbol, Int64} with 8 entries:
   :L3Cache  => 1
 ```
 
-
 ### Cache properties
 
 Assuming that multiple caches of the same level (e.g. L1) have identical properties, one can use the convenience functions `cachesize()` and `cachelinesize()` to obtain the relevant sizes in Bytes:
@@ -287,4 +286,71 @@ This is because `LibHwloc.hwloc_topology` are not garbage-collected (a call to
 `Hwloc.topology_init`, without a later call to `Hwloc.hwloc_topology_destroy`
 will leak memory). This is why `Hwloc.topology_load` calls
 `Hwloc.hwloc_topology_destroy` after creating the `Hwloc.Object` Julia object
-(which is garbage collected!).
\ No newline at end of file
+(which is garbage collected!).
+
+
+## Hwloc objects are `AbstractTrees`
+
+If the [`AbstractTrees`](https://github.com/JuliaCollections/AbstractTrees.jl)
+module is loaded, then passing an `Hwloc.Object` to `AbstractTrees.children`
+will construct an `HwlocTreeNode`. Calling `children(gettopology())` will
+return the Hwloc tree root:
+
+```julia
+julia> using AbstractTrees, Hwloc
+
+julia> t = children(gettopology());
+
+julia> print_tree(t; maxdepth=2)
+Hwloc.Object: Machine
+├─ Hwloc.Object: Package [L#0 P#0]
+│  ├─ Hwloc.Object: L3Cache
+│  │  ⋮
+│  │  
+│  └─ Hwloc.Object: NUMANode
+└─ Hwloc.Object: Bridge [HostBridge]
+   ├─ Hwloc.Object: PCI_Device [00:00.0 (HostBridge)]
+   ├─ Hwloc.Object: PCI_Device [00:02.0 (VGA)]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: PCI_Device [00:04.0 (SignalProcessing)]
+   ├─ Hwloc.Object: Bridge [PCIBridge]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: Bridge [PCIBridge]
+   ├─ Hwloc.Object: Bridge [PCIBridge]
+   ├─ Hwloc.Object: PCI_Device [00:0a.0 (SignalProcessing)]
+   ├─ Hwloc.Object: PCI_Device [00:0d.0 (USB)]
+   ├─ Hwloc.Object: PCI_Device [00:0d.2 (USB)]
+   ├─ Hwloc.Object: PCI_Device [00:0d.3 (USB)]
+   ├─ Hwloc.Object: PCI_Device [00:12.0 (Serial)]
+   ├─ Hwloc.Object: PCI_Device [00:14.0 (USB)]
+   ├─ Hwloc.Object: PCI_Device [00:14.2 (RAM)]
+   ├─ Hwloc.Object: PCI_Device [00:15.0 (SerialBus)]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: PCI_Device [00:15.1 (SerialBus)]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: PCI_Device [00:16.0 (Communication)]
+   ├─ Hwloc.Object: PCI_Device [00:19.0 (SerialBus)]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: PCI_Device [00:19.1 (SerialBus)]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: Bridge [PCIBridge]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: Bridge [PCIBridge]
+   │  ⋮
+   │  
+   ├─ Hwloc.Object: PCI_Device [00:1f.0 (ISABridge)]
+   ├─ Hwloc.Object: PCI_Device [00:1f.3 (MultimediaAudio)]
+   ├─ Hwloc.Object: PCI_Device [00:1f.4 (SMBus)]
+   └─ Hwloc.Object: PCI_Device [00:1f.5 (SerialBus)]
+
+```
+
+For examples of using the AbstracTree interface to search the Hwloc tree, see:
+[NetworkInterfaceControllers.jl](https://github.com/JuliaParallel/NetworkInterfaceControllers.jl)
\ No newline at end of file

From e016f4327efb92ccd070655d38d62dc1230a4a5d Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 10:47:02 -0800
Subject: [PATCH 29/36] oops! fixed it

---
 src/highlevel_api.jl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index fb0a34a..9e9f6b7 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -133,12 +133,12 @@ function print_topology(
         if no_newline
             print_topology(
                 io, child;
-                indent = indent, newline=newline, prefix = " + ", minimal=minimal
+                indent = indent, newline=false, prefix = " + ", minimal=minimal
             )
         else
             print_topology(
                 io, child;
-                indent = indent*repeat(" ", 4), newline=newline, minimal=minimal
+                indent = indent*repeat(" ", 4), newline=true, minimal=minimal
             )
         end
     end
@@ -146,7 +146,7 @@ function print_topology(
     for child in obj.io_children
         print_topology(
             io, child;
-            indent=indent*repeat(" ", 4), newline=newline, minimal=minimal
+            indent=indent*repeat(" ", 4), newline=true, minimal=minimal
         )
     end
 

From dcfe3ba369e597d4164abdd03e182b1fd04d6365 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 11:08:14 -0800
Subject: [PATCH 30/36] get_io -> io

---
 README.md            | 6 +++---
 src/highlevel_api.jl | 8 ++++----
 src/lowlevel_api.jl  | 8 ++++----
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index 6e038e1..f2cbf38 100644
--- a/README.md
+++ b/README.md
@@ -223,11 +223,11 @@ Hwloc.Object: Machine
 ### Do not include I/O devices in topology object
 
 You may prefer not to include I/O devices in you Hwloc tree, then we recommend
-passing the `get_io=false` (`true` by default) kwarg, in addition to `reload`
-(cf. above):
+passing the `io=false` (`true` by default) kwarg, in addition to `reload` (cf.
+above):
 
 ```julia
-julia> topo = gettopology(;reload=true, get_io=false)
+julia> topo = gettopology(;reload=true, io=false)
 Hwloc.Object: Machine
 
 julia> topology(topo)
diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 9e9f6b7..788acdc 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -160,10 +160,10 @@ Returns the top-level system topology `Object`.
 On first call, it loads the topology by querying libhwloc and caches the result.
 Pass `reload=true` in order to force reload.
 """
-function gettopology(htopo=nothing; reload=false, get_io=true)
+function gettopology(htopo=nothing; reload=false, io=true)
     if reload || (!isassigned(machine_topology))
         if isnothing(htopo)
-            htopo=topology_init(;get_io=get_io)
+            htopo=topology_init(;io=io)
         end
         machine_topology[] = topology_load(htopo)
     end
@@ -408,8 +408,8 @@ The quality of the result might depend on the used terminal and might vary betwe
 
 **Note:** The specific visualization may change between minor versions.
 """
-function topology_graphical(;get_io=true)
-    if get_io
+function topology_graphical(;io=true)
+    if io
         run(`$(lstopo_no_graphics()) --no-legend --of txt`)
     else
         run(`$(lstopo_no_graphics()) --no-io --no-legend --of txt`)
diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 8140654..63d9848 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -318,15 +318,15 @@ end
 
 
 """
-    topology_init(;get_io=true)
+    topology_init(;io=true)
 
 Init underlying Hwloc objec, and set the type filter to
-HWLOC_TYPE_FILTER_KEEP_ALL if `get_io==true`
+HWLOC_TYPE_FILTER_KEEP_ALL if `io==true`
 """
-function topology_init(;get_io=true)
+function topology_init(;io=true)
     r_htopo = Ref{hwloc_topology_t}()
     hwloc_topology_init(r_htopo)
-    if get_io
+    if io
         hwloc_topology_set_io_types_filter(
             r_htopo[], LibHwloc.HWLOC_TYPE_FILTER_KEEP_ALL
         )

From 3c6e5afedf75fefc701d1b675d46bffe2ebd3a99 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 15:24:15 -0800
Subject: [PATCH 31/36] Add iterator over I/O devices

---
 src/lowlevel_api.jl | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/lowlevel_api.jl b/src/lowlevel_api.jl
index 63d9848..b190725 100644
--- a/src/lowlevel_api.jl
+++ b/src/lowlevel_api.jl
@@ -238,7 +238,10 @@ IteratorSize(::Type{Object}) = Base.SizeUnknown()
 IteratorEltype(::Type{Object}) = Base.HasEltype()
 eltype(::Type{Object}) = Object
 isempty(::Object) = false
-iterate(obj::Object) = (obj, isempty(obj.memory_children) ? obj.children : vcat(obj.memory_children, obj.children))
+function iterate(obj::Object)
+    state = vcat(obj.children, obj.memory_children, obj.io_children)
+    return obj, state
+end
 function iterate(::Object, state::Vector{Object})
     isempty(state) && return nothing
     # depth-first traversal
@@ -246,6 +249,7 @@ function iterate(::Object, state::Vector{Object})
     obj, state = state[1], state[2:end]
     prepend!(state, obj.children)
     prepend!(state, obj.memory_children)
+    prepend!(state, obj.io_children)
     return obj, state
 end
 # length(obj::Object) = mapreduce(x->1, +, obj)

From 9b529e937d7aabe866b3409e6f63c48367ab0e91 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 15:53:16 -0800
Subject: [PATCH 32/36] Add all devices to getinfo

---
 src/highlevel_api.jl | 24 ++++++++++++++----------
 test/runtests.jl     |  4 ++--
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 788acdc..159f796 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -174,7 +174,7 @@ end
 """
 Prints the system topology as a tree.
 """
-topology(htopo=nothing) = print_topology(gettopology(htopo))
+topology(topo=gettopology()) = print_topology(topo)
 
 """
 Prints a summary of the system topology (loosely similar to `hwloc-info`).
@@ -200,21 +200,25 @@ function topology_info()
 end
 
 """
+    getinfo(topo=gettopology(); list_all=false)
+
 Programmatic version of `topology_info()`. Returns a `Dict{Symbol,Int}`
 whose entries indicate which and how often certain hwloc elements are present.
 
-If the keyword argument `list_all` (default: `false`) is set to `true`,
-the resulting dictionary will contain all possible hwloc elements.
+If the `list_all` kwarg is `true`, then the results Dict will have a key for
+each Hwloc type. **Warning:** a zero count does not necessarily mean that such
+a device is not present -- e.g. the following
+```
+getinfo(gettopology(;reload=true, io=false); list_all=true) 
+```
+will show a `PCI_Device` count of zero, even though those devices are present
+(the zero count is due to the `io=false` kwarg passed to `gettopology`).
 """
-function getinfo(; list_all::Bool = false)
+function getinfo(topo=gettopology(); list_all=false)
     res = list_all ? Dict{Symbol,Int}(t => 0 for t in obj_types) : Dict{Symbol, Int}()
-    for subobj in gettopology()
+    for subobj in topo
         t = hwloc_typeof(subobj)
-        if t in keys(res)
-            res[t] += 1
-        else
-            res[t] = 1
-        end
+        res[t] = get!(res, t, 0) + 1
     end
     return res
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 241a0e4..042d326 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -23,7 +23,7 @@ import CpuId
     @testset "Topology (compact info)" begin
         println("Info:")
         topology_info()
-        counts = getinfo(list_all=true)
+        counts = getinfo(;list_all=true)
         @test typeof(counts) == Dict{Symbol,Int}
         @test length(counts) == length(Hwloc.obj_types)
         println(counts)
@@ -34,7 +34,7 @@ import CpuId
         @test num_virtual_cores() == counts[:PU]
         @test num_packages() == counts[:Package]
         @test num_numa_nodes() == counts[:NUMANode]
-        counts = getinfo(list_all=false)
+        counts = getinfo()
         @test typeof(counts) == Dict{Symbol,Int}
         @test all(>(0), values(counts))
     end

From 7e4bd47615fd84c55a0f1a81fc3ebabbd80c8faf Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 15:57:05 -0800
Subject: [PATCH 33/36] Add PCI devices to topology_info

---
 README.md            | 24 +++++++++++++++---------
 src/highlevel_api.jl |  6 ++++--
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index f2cbf38..c0d9cc3 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,9 @@ Machine: 1 (31.05 GB)
      L1Cache: 4 (48.0 kB)
       Core: 4
        PU: 8
+        Bridge: 6
+         PCI_Device: 22
+          OS_Device: 13
 ```
 
 If you prefer a more verbose graphical visualization you may consider using `topology_graphical()`:
@@ -112,15 +115,18 @@ One may also use `getinfo()` to programmatically access some of the output of `t
 
 ```julia
 julia> getinfo()
-Dict{Symbol, Int64} with 8 entries:
-  :L2Cache  => 4
-  :NUMANode => 1
-  :Core     => 4
-  :Package  => 1
-  :L1Cache  => 4
-  :Machine  => 1
-  :PU       => 8
-  :L3Cache  => 1
+Dict{Symbol, Int64} with 11 entries:
+  :Package    => 1
+  :PU         => 8
+  :OS_Device  => 13
+  :Core       => 4
+  :L3Cache    => 1
+  :Machine    => 1
+  :PCI_Device => 22
+  :L2Cache    => 4
+  :NUMANode   => 1
+  :Bridge     => 6
+  :L1Cache    => 4
 ```
 
 
diff --git a/src/highlevel_api.jl b/src/highlevel_api.jl
index 159f796..371ec38 100644
--- a/src/highlevel_api.jl
+++ b/src/highlevel_api.jl
@@ -177,11 +177,13 @@ Prints the system topology as a tree.
 topology(topo=gettopology()) = print_topology(topo)
 
 """
+    topology_info(topo=gettopology())
+
 Prints a summary of the system topology (loosely similar to `hwloc-info`).
 """
-function topology_info()
+function topology_info(topo=gettopology())
     nodes = Tuple{Symbol, Int64, String}[]
-    for subobj in gettopology()
+    for subobj in topo
         idx = findfirst(t->t[1] == subobj.type_, nodes)
         if isnothing(idx)
             attrstr = ""

From 90afda0ba75ea64b146bd7cb18bee3eb4b7dc936 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 16:00:18 -0800
Subject: [PATCH 34/36] Update topology_graphical()

---
 README.md | 49 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 46 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index c0d9cc3..67f1f4c 100644
--- a/README.md
+++ b/README.md
@@ -85,9 +85,52 @@ Machine: 1 (31.05 GB)
 
 If you prefer a more verbose graphical visualization you may consider using `topology_graphical()`:
 
-<img width="1806" alt="Screenshot 2022-09-27 at 12 06 57" src="https://user-images.githubusercontent.com/187980/192498088-712d7ff0-c8ac-4535-b386-c08d3d0eddb3.png">
-
-(Note that as of now this may not produce colorful output on all systems.)
+```
+julia> topology_graphical()
+┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
+│ Machine (31GB total)                                                                                              │
+│                                                                                                                   │
+│ ┌────────────────────────────────────────────────────────────────────┐  ├┤╶─┬─────┬─────────────┐                 │
+│ │ Package L#0                                                        │      │     │ PCI 00:02.0 │                 │
+│ │                                                                    │      │     └─────────────┘                 │
+│ │ ┌────────────────────────────────────────────────────────────────┐ │      │                                     │
+│ │ │ NUMANode L#0 P#0 (31GB)                                        │ │      ├─────┼┤╶───────┬───────────────────┐ │
+│ │ └────────────────────────────────────────────────────────────────┘ │      │3.9       3.9  │ PCI 01:00.0       │ │
+│ │                                                                    │      │               │                   │ │
+│ │ ┌────────────────────────────────────────────────────────────────┐ │      │               │ ┌───────────────┐ │ │
+│ │ │ L3 (12MB)                                                      │ │      │               │ │ Block nvme0n1 │ │ │
+│ │ └────────────────────────────────────────────────────────────────┘ │      │               │ │               │ │ │
+│ │                                                                    │      │               │ │ 953 GB        │ │ │
+│ │ ┌─────────────┐  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐ │      │               │ └───────────────┘ │ │
+│ │ │ L2 (1280KB) │  │ L2 (1280KB) │  │ L2 (1280KB) │  │ L2 (1280KB) │ │      │               └───────────────────┘ │
+│ │ └─────────────┘  └─────────────┘  └─────────────┘  └─────────────┘ │      │                                     │
+│ │                                                                    │      ├─────┼┤╶───────┬──────────────────┐  │
+│ │ ┌────────────┐   ┌────────────┐   ┌────────────┐   ┌────────────┐  │      │0.6       0.6  │ PCI 72:00.0      │  │
+│ │ │ L1d (48KB) │   │ L1d (48KB) │   │ L1d (48KB) │   │ L1d (48KB) │  │      │               │                  │  │
+│ │ └────────────┘   └────────────┘   └────────────┘   └────────────┘  │      │               │ ┌──────────────┐ │  │
+│ │                                                                    │      │               │ │ Net wlp114s0 │ │  │
+│ │ ┌────────────┐   ┌────────────┐   ┌────────────┐   ┌────────────┐  │      │               │ └──────────────┘ │  │
+│ │ │ L1i (32KB) │   │ L1i (32KB) │   │ L1i (32KB) │   │ L1i (32KB) │  │      │               └──────────────────┘  │
+│ │ └────────────┘   └────────────┘   └────────────┘   └────────────┘  │      │                                     │
+│ │                                                                    │      └─────┼┤╶───────┬───────────────┐     │
+│ │ ┌────────────┐   ┌────────────┐   ┌────────────┐   ┌────────────┐  │       1.0            │ Block mmcblk0 │     │
+│ │ │ Core L#0   │   │ Core L#1   │   │ Core L#2   │   │ Core L#3   │  │                      │               │     │
+│ │ │            │   │            │   │            │   │            │  │                      │ 238 GB        │     │
+│ │ │ ┌────────┐ │   │ ┌────────┐ │   │ ┌────────┐ │   │ ┌────────┐ │  │                      └───────────────┘     │
+│ │ │ │ PU L#0 │ │   │ │ PU L#2 │ │   │ │ PU L#4 │ │   │ │ PU L#6 │ │  │                                            │
+│ │ │ │        │ │   │ │        │ │   │ │        │ │   │ │        │ │  │                                            │
+│ │ │ │  P#0   │ │   │ │  P#1   │ │   │ │  P#2   │ │   │ │  P#3   │ │  │                                            │
+│ │ │ └────────┘ │   │ └────────┘ │   │ └────────┘ │   │ └────────┘ │  │                                            │
+│ │ │ ┌────────┐ │   │ ┌────────┐ │   │ ┌────────┐ │   │ ┌────────┐ │  │                                            │
+│ │ │ │ PU L#1 │ │   │ │ PU L#3 │ │   │ │ PU L#5 │ │   │ │ PU L#7 │ │  │                                            │
+│ │ │ │        │ │   │ │        │ │   │ │        │ │   │ │        │ │  │                                            │
+│ │ │ │  P#4   │ │   │ │  P#5   │ │   │ │  P#6   │ │   │ │  P#7   │ │  │                                            │
+│ │ │ └────────┘ │   │ └────────┘ │   │ └────────┘ │   │ └────────┘ │  │                                            │
+│ │ └────────────┘   └────────────┘   └────────────┘   └────────────┘  │                                            │
+│ └────────────────────────────────────────────────────────────────────┘                                            │
+└───────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
+```
+(Note that as of now this may produce colorful output on some systems.)
 
 
 ## Obtaining particular information:

From 1f2135b80e4e044b227321f25b872862c2d554e9 Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 16:07:59 -0800
Subject: [PATCH 35/36] Update README to reflect changes to print_topology

---
 README.md | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 67f1f4c..8fab81b 100644
--- a/README.md
+++ b/README.md
@@ -29,24 +29,16 @@ Machine (31.05 GB)
     Package L#0 P#0 (31.05 GB)
         NUMANode (31.05 GB)
         L3 (12.0 MB)
-            L2 (1.25 MB)
-             + L1 (48.0 kB)
-             + Core L#0 P#0 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#0 P#0 
                 PU L#0 P#0 
                 PU L#1 P#4 
-            L2 (1.25 MB)
-             + L1 (48.0 kB)
-             + Core L#1 P#1 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#1 P#1 
                 PU L#2 P#1 
                 PU L#3 P#5 
-            L2 (1.25 MB)
-             + L1 (48.0 kB)
-             + Core L#2 P#2 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#2 P#2 
                 PU L#4 P#2 
                 PU L#5 P#6 
-            L2 (1.25 MB)
-             + L1 (48.0 kB)
-             + Core L#3 P#3 
+            L2 (1.25 MB) + L1 (48.0 kB) + Core L#3 P#3 
                 PU L#6 P#3 
                 PU L#7 P#7 
     HostBridge 

From 6d4c0e24b1374acca9d2db74cbc4ef832e84535f Mon Sep 17 00:00:00 2001
From: Johannes Blaschke <johannes@blaschke.science>
Date: Sat, 6 Jan 2024 16:09:21 -0800
Subject: [PATCH 36/36] typo

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 4fde833..b3d2719 100644
--- a/README.md
+++ b/README.md
@@ -288,7 +288,7 @@ Machine (31.05 GB)
                 PU L#6 P#3 
                 PU L#7 P#7 
 ```
-(note: to avoid caching by eccident, we recommend passing `reload=true` to
+(note: to avoid caching by accident, we recommend passing `reload=true` to
 `gettopology`)
 
 ### Low-level API for accessing the underlying topology object.