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[linux-fslc]: libtraceevent: Fix build with binutils 2.35 #95

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merged 1 commit into from
Aug 3, 2020

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@zandrey zandrey commented Aug 3, 2020

This is a cherry-pick of upstream commit to resolve build issues with upcoming update of binutils to version 2.35.

In binutils 2.35, 'nm -D' changed to show symbol versions along with
symbol names, with the usual @@ separator. When generating
libtraceevent-dynamic-list we need just the names, so strip off the
version suffix if present.

Signed-off-by: Ben Hutchings [email protected]
Tested-by: Salvatore Bonaccorso [email protected]
Reviewed-by: Steven Rostedt [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Arnaldo Carvalho de Melo [email protected]
(cherry picked from commit 39efdd9)
Signed-off-by: Andrey Zhizhikin [email protected]

In binutils 2.35, 'nm -D' changed to show symbol versions along with
symbol names, with the usual @@ separator.  When generating
libtraceevent-dynamic-list we need just the names, so strip off the
version suffix if present.

Signed-off-by: Ben Hutchings <[email protected]>
Tested-by: Salvatore Bonaccorso <[email protected]>
Reviewed-by: Steven Rostedt <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
(cherry picked from commit 39efdd9)
Signed-off-by: Andrey Zhizhikin <[email protected]>
@zandrey zandrey changed the title libtraceevent: Fix build with binutils 2.35 [linux-fslc]: libtraceevent: Fix build with binutils 2.35 Aug 3, 2020
@otavio otavio merged commit 96e9737 into Freescale:5.4.x+fslc Aug 3, 2020
zandrey pushed a commit to zandrey/linux-fslc that referenced this pull request Nov 19, 2020
commit fca3a45 upstream.

The minimum reserve size was adjusted to take into account the height of
the tree we are merging, however we can have a root with a level == 0.
What we want is root_level + 1 to get the number of nodes we may have to
cow.  This fixes the enospc_debug warning pops with btrfs/101.

Nikolay: this fixes failures on btrfs/060 btrfs/062 btrfs/063 and
btrfs/195 That I was seeing, the call trace was:

  [ 3680.515564] ------------[ cut here ]------------
  [ 3680.515566] BTRFS: block rsv returned -28
  [ 3680.515585] WARNING: CPU: 2 PID: 8339 at fs/btrfs/block-rsv.c:521 btrfs_use_block_rsv+0x162/0x180
  [ 3680.515587] Modules linked in:
  [ 3680.515591] CPU: 2 PID: 8339 Comm: btrfs Tainted: G        W         5.9.0-rc8-default Freescale#95
  [ 3680.515593] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
  [ 3680.515595] RIP: 0010:btrfs_use_block_rsv+0x162/0x180
  [ 3680.515600] RSP: 0018:ffffa01ac9753910 EFLAGS: 00010282
  [ 3680.515602] RAX: 0000000000000000 RBX: ffff984b34200000 RCX: 0000000000000027
  [ 3680.515604] RDX: 0000000000000027 RSI: 0000000000000000 RDI: ffff984b3bd19e28
  [ 3680.515606] RBP: 0000000000004000 R08: ffff984b3bd19e20 R09: 0000000000000001
  [ 3680.515608] R10: 0000000000000004 R11: 0000000000000046 R12: ffff984b264fdc00
  [ 3680.515609] R13: ffff984b13149000 R14: 00000000ffffffe4 R15: ffff984b34200000
  [ 3680.515613] FS:  00007f4e2912b8c0(0000) GS:ffff984b3bd00000(0000) knlGS:0000000000000000
  [ 3680.515615] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 3680.515617] CR2: 00007fab87122150 CR3: 0000000118e42000 CR4: 00000000000006e0
  [ 3680.515620] Call Trace:
  [ 3680.515627]  btrfs_alloc_tree_block+0x8b/0x340
  [ 3680.515633]  ? __lock_acquire+0x51a/0xac0
  [ 3680.515646]  alloc_tree_block_no_bg_flush+0x4f/0x60
  [ 3680.515651]  __btrfs_cow_block+0x14e/0x7e0
  [ 3680.515662]  btrfs_cow_block+0x144/0x2c0
  [ 3680.515670]  merge_reloc_root+0x4d4/0x610
  [ 3680.515675]  ? btrfs_lookup_fs_root+0x78/0x90
  [ 3680.515686]  merge_reloc_roots+0xee/0x280
  [ 3680.515695]  relocate_block_group+0x2ce/0x5e0
  [ 3680.515704]  btrfs_relocate_block_group+0x16e/0x310
  [ 3680.515711]  btrfs_relocate_chunk+0x38/0xf0
  [ 3680.515716]  btrfs_shrink_device+0x200/0x560
  [ 3680.515728]  btrfs_rm_device+0x1ae/0x6a6
  [ 3680.515744]  ? _copy_from_user+0x6e/0xb0
  [ 3680.515750]  btrfs_ioctl+0x1afe/0x28c0
  [ 3680.515755]  ? find_held_lock+0x2b/0x80
  [ 3680.515760]  ? do_user_addr_fault+0x1f8/0x418
  [ 3680.515773]  ? __x64_sys_ioctl+0x77/0xb0
  [ 3680.515775]  __x64_sys_ioctl+0x77/0xb0
  [ 3680.515781]  do_syscall_64+0x31/0x70
  [ 3680.515785]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported-by: Nikolay Borisov <[email protected]>
Fixes: 44d354a ("btrfs: relocation: review the call sites which can be interrupted by signal")
CC: [email protected] # 5.4+
Reviewed-by: Nikolay Borisov <[email protected]>
Tested-by: Nikolay Borisov <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio pushed a commit that referenced this pull request Dec 9, 2024
…address into one operation

commit 9e9e085 upstream.

When compiling kernel source 'make -j $(nproc)' with the up-and-running
KASAN-enabled kernel on a 256-core machine, the following soft lockup is
shown:

watchdog: BUG: soft lockup - CPU#28 stuck for 22s! [kworker/28:1:1760]
CPU: 28 PID: 1760 Comm: kworker/28:1 Kdump: loaded Not tainted 6.10.0-rc5 #95
Workqueue: events drain_vmap_area_work
RIP: 0010:smp_call_function_many_cond+0x1d8/0xbb0
Code: 38 c8 7c 08 84 c9 0f 85 49 08 00 00 8b 45 08 a8 01 74 2e 48 89 f1 49 89 f7 48 c1 e9 03 41 83 e7 07 4c 01 e9 41 83 c7 03 f3 90 <0f> b6 01 41 38 c7 7c 08 84 c0 0f 85 d4 06 00 00 8b 45 08 a8 01 75
RSP: 0018:ffffc9000cb3fb60 EFLAGS: 00000202
RAX: 0000000000000011 RBX: ffff8883bc4469c0 RCX: ffffed10776e9949
RDX: 0000000000000002 RSI: ffff8883bb74ca48 RDI: ffffffff8434dc50
RBP: ffff8883bb74ca40 R08: ffff888103585dc0 R09: ffff8884533a1800
R10: 0000000000000004 R11: ffffffffffffffff R12: ffffed1077888d39
R13: dffffc0000000000 R14: ffffed1077888d38 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8883bc400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005577b5c8d158 CR3: 0000000004850000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 ? watchdog_timer_fn+0x2cd/0x390
 ? __pfx_watchdog_timer_fn+0x10/0x10
 ? __hrtimer_run_queues+0x300/0x6d0
 ? sched_clock_cpu+0x69/0x4e0
 ? __pfx___hrtimer_run_queues+0x10/0x10
 ? srso_return_thunk+0x5/0x5f
 ? ktime_get_update_offsets_now+0x7f/0x2a0
 ? srso_return_thunk+0x5/0x5f
 ? srso_return_thunk+0x5/0x5f
 ? hrtimer_interrupt+0x2ca/0x760
 ? __sysvec_apic_timer_interrupt+0x8c/0x2b0
 ? sysvec_apic_timer_interrupt+0x6a/0x90
 </IRQ>
 <TASK>
 ? asm_sysvec_apic_timer_interrupt+0x16/0x20
 ? smp_call_function_many_cond+0x1d8/0xbb0
 ? __pfx_do_kernel_range_flush+0x10/0x10
 on_each_cpu_cond_mask+0x20/0x40
 flush_tlb_kernel_range+0x19b/0x250
 ? srso_return_thunk+0x5/0x5f
 ? kasan_release_vmalloc+0xa7/0xc0
 purge_vmap_node+0x357/0x820
 ? __pfx_purge_vmap_node+0x10/0x10
 __purge_vmap_area_lazy+0x5b8/0xa10
 drain_vmap_area_work+0x21/0x30
 process_one_work+0x661/0x10b0
 worker_thread+0x844/0x10e0
 ? srso_return_thunk+0x5/0x5f
 ? __kthread_parkme+0x82/0x140
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x2a5/0x370
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x30/0x70
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Debugging Analysis:

  1. The following ftrace log shows that the lockup CPU spends too much
     time iterating vmap_nodes and flushing TLB when purging vm_area
     structures. (Some info is trimmed).

     kworker: funcgraph_entry:              |  drain_vmap_area_work() {
     kworker: funcgraph_entry:              |   mutex_lock() {
     kworker: funcgraph_entry:  1.092 us    |     __cond_resched();
     kworker: funcgraph_exit:   3.306 us    |   }
     ...                                        ...
     kworker: funcgraph_entry:              |    flush_tlb_kernel_range() {
     ...                                          ...
     kworker: funcgraph_exit: # 7533.649 us |    }
     ...                                         ...
     kworker: funcgraph_entry:  2.344 us    |   mutex_unlock();
     kworker: funcgraph_exit: $ 23871554 us | }

     The drain_vmap_area_work() spends over 23 seconds.

     There are 2805 flush_tlb_kernel_range() calls in the ftrace log.
       * One is called in __purge_vmap_area_lazy().
       * Others are called by purge_vmap_node->kasan_release_vmalloc.
         purge_vmap_node() iteratively releases kasan vmalloc
         allocations and flushes TLB for each vmap_area.
           - [Rough calculation] Each flush_tlb_kernel_range() runs
             about 7.5ms.
               -- 2804 * 7.5ms = 21.03 seconds.
               -- That's why a soft lock is triggered.

  2. Extending the soft lockup time can work around the issue (For example,
     # echo 60 > /proc/sys/kernel/watchdog_thresh). This confirms the
     above-mentioned speculation: drain_vmap_area_work() spends too much
     time.

If we combine all TLB flush operations of the KASAN shadow virtual
address into one operation in the call path
'purge_vmap_node()->kasan_release_vmalloc()', the running time of
drain_vmap_area_work() can be saved greatly. The idea is from the
flush_tlb_kernel_range() call in __purge_vmap_area_lazy(). And, the
soft lockup won't be triggered.

Here is the test result based on 6.10:

[6.10 wo/ the patch]
  1. ftrace latency profiling (record a trace if the latency > 20s).
     echo 20000000 > /sys/kernel/debug/tracing/tracing_thresh
     echo drain_vmap_area_work > /sys/kernel/debug/tracing/set_graph_function
     echo function_graph > /sys/kernel/debug/tracing/current_tracer
     echo 1 > /sys/kernel/debug/tracing/tracing_on

  2. Run `make -j $(nproc)` to compile the kernel source

  3. Once the soft lockup is reproduced, check the ftrace log:
     cat /sys/kernel/debug/tracing/trace
        # tracer: function_graph
        #
        # CPU  DURATION                  FUNCTION CALLS
        # |     |   |                     |   |   |   |
          76) $ 50412985 us |    } /* __purge_vmap_area_lazy */
          76) $ 50412997 us |  } /* drain_vmap_area_work */
          76) $ 29165911 us |    } /* __purge_vmap_area_lazy */
          76) $ 29165926 us |  } /* drain_vmap_area_work */
          91) $ 53629423 us |    } /* __purge_vmap_area_lazy */
          91) $ 53629434 us |  } /* drain_vmap_area_work */
          91) $ 28121014 us |    } /* __purge_vmap_area_lazy */
          91) $ 28121026 us |  } /* drain_vmap_area_work */

[6.10 w/ the patch]
  1. Repeat step 1-2 in "[6.10 wo/ the patch]"

  2. The soft lockup is not triggered and ftrace log is empty.
     cat /sys/kernel/debug/tracing/trace
     # tracer: function_graph
     #
     # CPU  DURATION                  FUNCTION CALLS
     # |     |   |                     |   |   |   |

  3. Setting 'tracing_thresh' to 10/5 seconds does not get any ftrace
     log.

  4. Setting 'tracing_thresh' to 1 second gets ftrace log.
     cat /sys/kernel/debug/tracing/trace
     # tracer: function_graph
     #
     # CPU  DURATION                  FUNCTION CALLS
     # |     |   |                     |   |   |   |
       23) $ 1074942 us  |    } /* __purge_vmap_area_lazy */
       23) $ 1074950 us  |  } /* drain_vmap_area_work */

  The worst execution time of drain_vmap_area_work() is about 1 second.

Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 282631c ("mm: vmalloc: remove global purge_vmap_area_root rb-tree")
Signed-off-by: Adrian Huang <[email protected]>
Co-developed-by: Uladzislau Rezki (Sony) <[email protected]>
Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
Tested-by: Jiwei Sun <[email protected]>
Reviewed-by: Baoquan He <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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3 participants