Waiman Long
9f1f4e9503
mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup() ...
commit d1534ae23c2b6be350c8ab060803fbf6e9682adc upstream.
A soft lockup warning was observed on a relative small system x86-64
system with 16 GB of memory when running a debug kernel with kmemleak
enabled.
watchdog: BUG: soft lockup - CPU#8 stuck for 33s! [kworker/8:1:134]
The test system was running a workload with hot unplug happening in
parallel. Then kemleak decided to disable itself due to its inability to
allocate more kmemleak objects. The debug kernel has its
CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE set to 40,000.
The soft lockup happened in kmemleak_do_cleanup() when the existing
kmemleak objects were being removed and deleted one-by-one in a loop via a
workqueue. In this particular case, there are at least 40,000 objects
that need to be processed and given the slowness of a debug kernel and the
fact that a raw_spinlock has to be acquired and released in
__delete_object(), it could take a while to properly handle all these
objects.
As kmemleak has been disabled in this case, the object removal and
deletion process can be further optimized as locking isn't really needed.
However, it is probably not worth the effort to optimize for such an edge
case that should rarely happen. So the simple solution is to call
cond_resched() at periodic interval in the iteration loop to avoid soft
lockup.
Link: https://lkml.kernel.org/r/20250728190248.605750-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:21:30 +02:00
panic: Consolidate open-coded panic_on_warn checks
2023-02-06 07:52:50 +01:00
mm/cma: use nth_page() in place of direct struct page manipulation
2023-11-28 16:50:19 +00:00
mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations
2024-04-13 12:51:34 +02:00
mm: allow a controlled amount of unfairness in the page lock
2023-08-30 16:27:26 +02:00
v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails
2022-12-08 11:23:06 +01:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
2022-12-19 12:24:15 +01:00
mm/huge_memory: fix dereferencing invalid pmd migration entry
2025-06-27 11:02:58 +01:00
mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
2022-12-19 12:24:15 +01:00
mm/khugepaged: fix collapse_pte_mapped_thp() to allow anon_vma
2023-01-24 07:18:01 +01:00
mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup()
2025-08-28 16:21:30 +02:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
mm: fix madivse_pageout mishandling on non-LRU page
2022-10-05 10:37:43 +02:00
Revert "mm: Always release pages to the buddy allocator in memblock_free_late()."
2023-02-22 12:50:39 +01:00
memcg: always call cond_resched() after fn()
2025-06-04 14:32:35 +02:00
memfd: fix F_SEAL_WRITE after shmem huge page allocated
2022-03-08 19:07:49 +01:00
mm/memory-failure: fix an incorrect use of tail pages
2024-04-13 12:51:31 +02:00
mm: avoid leaving partial pfn mappings around in error case
2024-11-17 14:58:53 +01:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
memtest: use {READ,WRITE}_ONCE in memory scanning
2024-04-13 12:51:27 +02:00
mm/migrate: set swap entry values of THP tail pages properly.
2024-04-13 12:51:31 +02:00
mm: Fix TLB flush for not-first PFNMAP mappings in unmap_region()
2022-09-20 12:28:00 +02:00
mm/khugepaged: fix GUP-fast interaction by sending IPI
2022-12-14 11:30:42 +01:00
arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
2022-05-15 19:54:46 +02:00
mm/mremap: hold the rmap lock in write mode when moving page table entries.
2022-08-25 11:17:20 +02:00
memcg: fix soft lockup in the OOM process
2025-03-13 12:43:21 +01:00
mm: fix ratelimit_pages update error in dirty_ratio_handler()
2025-06-27 11:02:52 +01:00
mm/page_alloc.c: avoid infinite retries caused by cpuset race
2025-06-04 14:32:36 +02:00
mm: fix unexpected zeroed page mapping with zram swap
2022-05-12 12:23:48 +02:00
mm: pagewalk: Fix race between unmap and page walker
2022-10-15 07:54:36 +02:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
vfs: fix readahead(2) on block devices
2023-11-20 10:30:08 +01:00
mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse
2022-09-05 10:27:46 +02:00
mm: revert "mm: shmem: fix data-race in shmem_getattr()"
2024-12-14 19:44:19 +01:00
mm: krealloc: Fix MTE false alarm in __do_krealloc
2024-11-08 16:20:54 +01:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
treewide: Remove uninitialized_var() usage
2023-06-09 10:29:01 +02:00
mm/swapfile: skip HugeTLB pages for unuse_vma
2024-11-08 16:20:47 +01:00
mm/usercopy: return 1 from hardened_usercopy __setup() handler
2022-04-15 14:18:30 +02:00
userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb
2024-03-01 13:13:33 +01:00
mm: only enforce minimum stack gap size if it's sensible
2024-11-08 16:20:35 +01:00
mm: add missing release barrier on PGDAT_RECLAIM_LOCKED unlock
2025-05-02 07:39:16 +02:00
arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
2022-05-15 19:54:46 +02:00
zsmalloc: fix races between asynchronous zspage free and page migration
2022-06-06 08:33:50 +02:00
9f1f4e9503