Alter PAGE_SIZE usage #534

mjp41 · 2022-05-30T13:51:23Z

Using PAGE_SIZE as the minimum size of the CHUNK means that if this is
configured to 2MiB, then there is a gap between
MAX_SMALL_SIZECLASS_SIZE, and MIN_CHUNK_SIZE, and thus
we can't represent certain sizes.

This removes that connection, and adds a static assert to check for the issue.

mjp41 · 2022-05-30T13:53:20Z

#485 I believe this will fix the crashes that @misakikasumi observed when trying to build Windows Huge page support.

mjp41 · 2022-05-30T13:54:45Z

@nwf-msr this primarily affects your PowerPC setup, so if you could make sure I haven't broken anything that would be great.

nwf-msr · 2022-05-30T15:20:42Z

This breaks a debug build of snmalloc on my PowerPC machine; many of the -check tests fail. With apologies, the call stack is below.

Starting program: /cheri/build/mainline/snmalloc2-native-build/func-memory-check
warning: Error disabling address space randomization: Operation not permitted
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/powerpc64le-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
snmalloc::BuddyInplaceRep::set (ptr=0x7ebfa8479000, r=...) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:37
37                reinterpret_cast<FreeChunk*>((*ptr).unsafe_uintptr() & MASK));
(gdb) bt
#0  snmalloc::BuddyInplaceRep::set (ptr=0x7ebfa8479000, r=...) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:37
#1  0x000000001004dc18 in snmalloc::RBTree<snmalloc::BuddyInplaceRep, true, false>::ChildRef::operator= (this=0x7fffd1dd8dd8, t=...) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/../ds/../pal/../aal/../ds_core/redblacktree.h:134
#2  0x000000001004f240 in snmalloc::RBTree<snmalloc::BuddyInplaceRep, true, false>::insert_path (
    this=0x10090878 <snmalloc::StaticParent<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, sn
malloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyR
ange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>,
14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pa
geMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::parent+72>, path=..., value=...) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/../ds/../pal/../aal/../ds_core/redblacktree.h:649
#3  0x000000001004c4f4 in snmalloc::Buddy<snmalloc::BuddyInplaceRep, 4ul, 14ul>::add_block (
    this=0x10090838 <snmalloc::StaticParent<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, sn
malloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyR
ange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>,
14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pa
geMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::parent+8>, addr=..., size=4096) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/buddy.h:85
#4  0x000000001005057c in snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagema
p<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyRange<24ul, 63ul, s
nmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::Pa
gemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>
, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::add_range(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long)::{lambda(snmalloc::CapPtr<void, snma
lloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long, bool)#1}::operator()(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::Addr
essSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long, bool) const (this=0x7fffd1dd9958, base=..., align=4096) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:165
#5  0x0000000010050480 in snmalloc::range_to_pow_2_blocks<4ul, snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snm
alloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, sn
malloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pag
eMapEntry, false>, 14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::P
ALLinux, false>::PageMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::add_range(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long)
::{lambda(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long, bool)#1}>(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmallo
c::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long, snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::Backen
dAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmall
oc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::Backen
dAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, fals
e>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::add_range(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr
::dimension::Wildness)1> >, unsigned long)::{lambda(snmalloc::CapPtr<void, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)1, (snmalloc::capptr::dimension::AddressSpaceControl)1, (snmalloc::capptr::dimension::Wildness)1> >, unsigned long, bool)#1}) (base=..., length=12288, f=...)
    at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/range_helpers.h:30
#6  0x0000000010050270 in snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagema
p<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyRange<24ul, 63ul, s
nmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::Pa
gemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>
, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::add_range (
    this=0x10090830 <snmalloc::StaticParent<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, sn
malloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyR
ange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>,
14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pa
geMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::parent>, base=..., length=12288) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:162
#7  0x00000000100501f4 in snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagema
p<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyRange<24ul, 63ul, s
nmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::Pa
gemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>
, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::refill (
    this=0x10090830 <snmalloc::StaticParent<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, sn
malloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyR
ange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>,
14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pa
geMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::parent>, size=4096) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:177
#8  0x0000000010050110 in snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagema
p<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyRange<24ul, 63ul, s
nmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::Pa
gemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>
, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > >::alloc_range (
    this=0x10090830 <snmalloc::StaticParent<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, sn
malloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBuddyR
ange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>,
14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::Pa
geMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::parent>, size=4096) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/smallbuddyrange.h:210
#9  0x0000000010041cc8 in snmalloc::GlobalRange<snmalloc::SmallBuddyRange<snmalloc::StatsRange<snmalloc::CommitRange<snmalloc::PALLinux, snmalloc::GlobalRange<snmalloc::LogRange<4ul, snmalloc::LargeBuddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux
, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, false>, 14ul, snmalloc::SubRange<snmalloc::PALLinux, 6ul, snmalloc::GlobalRange<snmalloc::LogRange<2ul, snmalloc::LargeBu
ddyRange<24ul, 63ul, snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, fals
e>, 14ul, snmalloc::PagemapRegisterRange<snmalloc::BasicPagemap<snmalloc::BackendAllocator<snmalloc::PALLinux, false>, snmalloc::PALLinux, snmalloc::FlatPagemap<14ul, snmalloc::BackendAllocator<snmalloc::PALLinux, false>::PageMapEntry, snmalloc::PALLinux, false>, snmalloc::BackendAllocator<snmalloc::PALLinux, false>
::PageMapEntry, false>, true, snmalloc::PalRange<snmalloc::PALLinux> > > > > > > > > > > > >::alloc_range (this=0x7fffd1dd9d00, size=4096) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/globalrange.h:39
#10 0x00000000100410cc in snmalloc::BackendAllocator<snmalloc::PALLinux, false>::alloc_meta_data<snmalloc::CoreAllocator<snmalloc::Globals> > (local_state=0x0, size=2304) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend/../backend/backend.h:247
#11 0x000000001003e940 in snmalloc::Pool<snmalloc::CoreAllocator<snmalloc::Globals>, snmalloc::Globals, &snmalloc::Globals::pool>::acquire<snmalloc::LocalCache*> (args=@0x7fffd1dd9eb8: 0x7fffa8dd5640) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/pool.h:135
#12 0x000000001003e4dc in snmalloc::LocalAllocator<snmalloc::Globals>::init (this=0x7fffa8dd5640) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localalloc.h:383
#13 0x0000000010061c98 in snmalloc::LocalAllocator<snmalloc::Globals>::lazy_init<snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned long)::{lambda(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension
::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*)#1}::operator()(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmal
loc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*) const::{lambda(snmallo
c::CoreAllocator<snmalloc::Globals>*, unsigned long)#1}, unsigned long>(snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned long)::{lambda(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::Address
SpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*)#1}::operator()(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capp
tr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*) const::{lambda(snmalloc::CoreAl
locator<snmalloc::Globals>*, unsigned long)#1}, unsigned long) (this=0x7fffa8dd5640, action=..., args=0) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localalloc.h:138
#14 0x000000001002f5c8 in snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned long)::{lambda(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::
Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*)#1}::operator()(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::d
--Type <RET> for more, q to quit, c to continue without paging--
imension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*) const (this=0x7fffd1de2808, sizeclass=0, fl=0x7fffa8dd5640)
    at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localalloc.h:235
#15 snmalloc::LocalCache::alloc<(snmalloc::ZeroMem)0, snmalloc::Globals, snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned long)::{lambda(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::Addres
sSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*)#1}, snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned l
ong)::{lambda(snmalloc::CapPtr<snmalloc::freelist::Object::T<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension
::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >)#1}>(snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0>(unsigned long)::{lambda(snmalloc::CapPtr<snmalloc::freelist::Object::T<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension
::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >)#1}, unsigned long, snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmallo
c::ZeroMem)0>(unsigned long)::{lambda(unsigned long, snmalloc::freelist::Iter<snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::capptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)1>, snmalloc::capptr::bound<(snmalloc::capptr::dimension::Spatial)0, (snmalloc::ca
pptr::dimension::AddressSpaceControl)0, (snmalloc::capptr::dimension::Wildness)0> >*)#1}) (this=0x7fffa8dd5640, domesticate=..., size=16, slowpath=...) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localcache.h:113
#16 snmalloc::LocalAllocator<snmalloc::Globals>::small_alloc<(snmalloc::ZeroMem)0> (this=0x7fffa8dd5640, size=16) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localalloc.h:242
#17 snmalloc::LocalAllocator<snmalloc::Globals>::alloc<(snmalloc::ZeroMem)0> (this=0x7fffa8dd5640, size=16) at /cheri/source/mainline/snmalloc2/src/snmalloc/backend_helpers/../mem/localalloc.h:442
#18 test_alloc_dealloc_64k () at /cheri/source/mainline/snmalloc2/src/test/func/memory/memory.cc:97
#19 0x000000001003bc40 in main (argc=1, argv=0x7fffd1de2f18) at /cheri/source/mainline/snmalloc2/src/test/func/memory/memory.cc:542

nwf-msr · 2022-05-30T15:51:05Z

Ah, a little prodding and some belated understanding:

snmalloc/src/snmalloc/backend_helpers/smallbuddyrange.h

Lines 172 to 180 in 1b8aa6b

    
           capptr::Chunk<void> refill(size_t size) 
        
           { 
        
             auto refill = parent.alloc_range(MIN_CHUNK_SIZE); 
        
             if (refill != nullptr) 
        
               add_range(pointer_offset(refill, size), MIN_CHUNK_SIZE - size); 
        
             return refill; 
        
           }

needs to grab things in multiples of OS_PAGE_SIZE otherwise the mprotect inside

snmalloc/src/snmalloc/pal/pal_posix.h

Lines 227 to 242 in 1b8aa6b

    
           template<ZeroMem zero_mem> 
        
           static void notify_using(void* p, size_t size) noexcept 
        
           { 
        
             SNMALLOC_ASSERT( 
        
               is_aligned_block<OS::page_size>(p, size) || (zero_mem == NoZero)); 
        
             if constexpr (PalEnforceAccess) 
        
               mprotect(p, size, PROT_READ | PROT_WRITE); 
        
             else 
        
             { 
        
               UNUSED(p, size); 
        
             } 
        
             if constexpr (zero_mem == YesZero) 
        
               zero<true>(p, size); 
        
           }

will return EINVAL (as it is here; should we SNMALLOC_ASSERT on that returning 0?). The assert isn't saving us because CommitRange passes NoZero:

snmalloc/src/snmalloc/backend_helpers/commitrange.h

Lines 26 to 32 in 1b8aa6b

    
           capptr::Chunk<void> alloc_range(size_t size) 
        
           { 
        
             auto range = parent.alloc_range(size); 
        
             if (range != nullptr) 
        
               PAL::template notify_using<NoZero>(range.unsafe_ptr(), size); 
        
             return range; 
        
           }

Maybe the PAL's assertion should actually be

is_aligned_block<OS::page_size>(p, size) || (!PalEnforceAccess && (zero_mem == NoZero))

or maybe just

is_aligned_block<OS::page_size>(p, size)

since PalEnforceAccess is a static, global configuration knob?

mjp41 · 2022-05-30T20:23:31Z

Moving to draft. To fix this issue is going to conflict with #530. To fix, we need

Explicit OS_PAGE_SIZE as the minimum size for the LargeBuddyRange in a few places so that we don't make sub page requests to the CommitRange.
Add assert to CommitRange, so it fails more cleanly
Probably a static_assert to check minimium size <= request_size on LargeBuddyRange.

Using PAGE_SIZE as the minimum size of the CHUNK means that if this is configured to 2MiB, then there is a gap between MAX_SMALL_SIZECLASS_SIZE, and MIN_CHUNK_SIZE, and thus we can't represent certain sizes,

nwf-msr

LGTM and passes on POWER

mjp41 requested a review from nwf-msr May 30, 2022 13:54

mjp41 force-pushed the huge_page_prep branch from bf61372 to 9cdf0d7 Compare May 30, 2022 13:56

mjp41 marked this pull request as draft May 30, 2022 20:20

mjp41 added 3 commits May 31, 2022 11:55

Sanity check on parameters to large buddy.

4b3de94

Check commit occurs at page granularity

d517585

Alter PAGE_SIZE usage

23f50a1

Using PAGE_SIZE as the minimum size of the CHUNK means that if this is configured to 2MiB, then there is a gap between MAX_SMALL_SIZECLASS_SIZE, and MIN_CHUNK_SIZE, and thus we can't represent certain sizes,

mjp41 force-pushed the huge_page_prep branch from 9cdf0d7 to 23f50a1 Compare May 31, 2022 12:23

nwf-msr approved these changes May 31, 2022

View reviewed changes

mjp41 marked this pull request as ready for review May 31, 2022 12:59

mjp41 merged commit 53d9fd2 into microsoft:main May 31, 2022

mjp41 deleted the huge_page_prep branch May 31, 2022 12:59

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Alter PAGE_SIZE usage #534

Alter PAGE_SIZE usage #534

mjp41 commented May 30, 2022

mjp41 commented May 30, 2022

mjp41 commented May 30, 2022

nwf-msr commented May 30, 2022

nwf-msr commented May 30, 2022

mjp41 commented May 30, 2022

nwf-msr left a comment

Alter PAGE_SIZE usage #534

Alter PAGE_SIZE usage #534

Conversation

mjp41 commented May 30, 2022

mjp41 commented May 30, 2022

mjp41 commented May 30, 2022

nwf-msr commented May 30, 2022

nwf-msr commented May 30, 2022

mjp41 commented May 30, 2022

nwf-msr left a comment

Choose a reason for hiding this comment