Linus Torvalds 9b1ea29bc0 Revert "mm, slub: consider rest of partial list if acquire_slab() fails" ... This reverts commit 8ff60eb052. The kernel test robot reports a huge performance regression due to the commit, and the reason seems fairly straightforward: when there is contention on the page list (which is what causes acquire_slab() to fail), we do _not_ want to just loop and try again, because that will transfer the contention to the 'n->list_lock' spinlock we hold, and just make things even worse. This is admittedly likely a problem only on big machines - the kernel test robot report comes from a 96-thread dual socket Intel Xeon Gold 6252 setup, but the regression there really is quite noticeable: -47.9% regression of stress-ng.rawpkt.ops_per_sec and the commit that was marked as being fixed (7ced371971: "slub: Acquire_slab() avoid loop") actually did the loop exit early very intentionally (the hint being that "avoid loop" part of that commit message), exactly to avoid this issue. The correct thing to do may be to pick some kind of reasonable middle ground: instead of breaking out of the loop on the very first sign of contention, or trying over and over and over again, the right thing may be to re-try _once_, and then give up on the second failure (or pick your favorite value for "once"..). Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/lkml/20210301080404.GF12822@xsang-OptiPlex-9020/ Cc: Jann Horn <jannh@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-03-10 10:18:04 -08:00
..
kasan	kasan: clarify that only first bug is reported in HW_TAGS	2021-02-26 09:41:03 -08:00
kfence	kfence: use error_report_end tracepoint	2021-02-26 09:41:02 -08:00
backing-dev.c	mm/backing-dev.c: use might_alloc()	2021-02-26 09:41:01 -08:00
balloon_compaction.c
cleancache.c
cma.c	mm: cma: print region name on failure	2021-02-26 09:41:00 -08:00
cma.h
cma_debug.c
compaction.c	mm, compaction: make fast_isolate_freepages() stay within zone	2021-02-24 13:38:34 -08:00
debug.c	mm/debug: improve memcg debugging	2021-02-24 13:38:27 -08:00
debug_page_ref.c
debug_vm_pgtable.c	mm/debug_vm_pgtable/basic: iterate over entire protection_map[]	2021-02-24 13:38:27 -08:00
dmapool.c	mm/dmapool: use might_alloc()	2021-02-26 09:41:01 -08:00
early_ioremap.c	mm/early_ioremap.c: use __func__ instead of function name	2021-02-26 09:41:02 -08:00
fadvise.c
failslab.c
filemap.c	mm: pass pvec directly to find_get_entries	2021-02-26 09:40:59 -08:00
frontswap.c
gup.c	mm/hugetlb: grab head page refcount once for group of subpages	2021-02-24 13:38:32 -08:00
gup_test.c	mm/gup_test.c: mark gup_test_init as __init function	2020-12-15 12:13:38 -08:00
gup_test.h	selftests/vm: gup_test: introduce the dump_pages() sub-test	2020-12-15 12:13:38 -08:00
highmem.c	mm/highmem: prepare for overriding set_pte_at()	2021-01-24 10:34:52 -08:00
hmm.c
huge_memory.c	mm,thp,shmem: limit shmem THP alloc gfp_mask	2021-02-26 09:40:59 -08:00
hugetlb.c	mm/hugetlb: change hugetlb_reserve_pages() to type bool	2021-02-24 13:38:35 -08:00
hugetlb_cgroup.c	hugetlb_cgroup: use helper pages_per_huge_page() in hugetlb_cgroup	2021-02-24 13:38:33 -08:00
hwpoison-inject.c
init-mm.c	mm/gup: prevent gup_fast from racing with COW during fork	2020-12-15 12:13:39 -08:00
internal.h	mm: add and use find_lock_entries	2021-02-26 09:40:59 -08:00
interval_tree.c
ioremap.c
Kconfig	media: videobuf2: Move frame_vector into media subsystem	2021-01-12 14:15:31 +01:00
Kconfig.debug	mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO	2020-12-15 12:13:46 -08:00
khugepaged.c	mm,thp,shmem: make khugepaged obey tmpfs mount flags	2021-02-26 09:40:59 -08:00
kmemleak.c
ksm.c	mm: cleanup kstrto*() usage	2020-12-15 12:13:47 -08:00
list_lru.c	mm/list_lru.c: remove kvfree_rcu_local()	2021-02-24 13:38:30 -08:00
maccess.c
madvise.c	idmapped-mounts-v5.12	2021-02-23 13:39:45 -08:00
Makefile	mm: add Kernel Electric-Fence infrastructure	2021-02-26 09:41:02 -08:00
mapping_dirty_helpers.c	mm/mapping_dirty_helpers: enhance the kernel-doc markups	2020-12-15 12:13:41 -08:00
memblock.c	memblock: remove return value of memblock_free_all()	2021-02-22 13:01:23 -08:00
memcontrol.c	mm: memcontrol: fix get_active_memcg return value	2021-02-24 13:38:30 -08:00
memfd.c
memory-failure.c	mm: fix memory_failure() handling of dax-namespace metadata	2021-02-26 09:41:00 -08:00
memory.c	MIPS: make userspace mapping young by default	2021-02-26 09:41:05 -08:00
memory_hotplug.c	mm/memory_hotplug: prevalidate the address range being added with platform	2021-02-26 09:41:00 -08:00
mempolicy.c	mm/mempolicy: use helper range_in_vma() in queue_pages_test_walk()	2021-02-24 13:38:34 -08:00
mempool.c	kasan: move _RET_IP_ to inline wrappers	2021-02-24 13:38:31 -08:00
memremap.c	mm/memory_hotplug: prevalidate the address range being added with platform	2021-02-26 09:41:00 -08:00
memtest.c
migrate.c	mm: memcg: add swapcache stat for memcg v2	2021-02-24 13:38:29 -08:00
mincore.c	inode: make init and permission helpers idmapped mount aware	2021-01-24 14:27:16 +01:00
mlock.c	mm/mlock: stop counting mlocked pages when none vma is found	2021-02-26 09:41:01 -08:00
mm_init.c	mm: fix fall-through warnings for Clang	2020-12-15 12:13:47 -08:00
mmap.c	mm/mmap.c: remove unnecessary local variable	2021-02-24 13:38:30 -08:00
mmap_lock.c	mm: mmap_lock: add tracepoints around lock acquisition	2020-12-15 12:13:41 -08:00
mmu_gather.c	tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu()	2021-01-29 20:02:29 +01:00
mmu_notifier.c	mm: track mmu notifiers in fs_reclaim_acquire/release	2020-12-15 12:13:41 -08:00
mmzone.c	mm/lru: replace pgdat lru_lock with lruvec lock	2020-12-15 14:48:04 -08:00
mprotect.c	mm/mprotect.c: optimize error detection in do_mprotect_pkey()	2021-02-24 13:38:30 -08:00
mremap.c	mm: mremap: unlink anon_vmas when mremap with MREMAP_DONTUNMAP success	2021-02-24 13:38:30 -08:00
msync.c
nommu.c	mm/nommu: Fix return type of filemap_map_pages()	2021-01-28 14:10:31 +00:00
oom_kill.c	mm, oom: fix a comment in dump_task()	2021-02-24 13:38:34 -08:00
page-writeback.c	mm: make wait_on_page_writeback() wait for multiple pending writebacks	2021-01-05 11:33:00 -08:00
page_alloc.c	mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo	2021-02-26 09:41:00 -08:00
page_counter.c	mm/page_counter: use page_counter_read in page_counter_set_max	2020-12-15 12:13:40 -08:00
page_ext.c	mm: fix some spelling mistakes in comments	2020-12-15 22:46:19 -08:00
page_idle.c	mm: page_idle_get_page() does not need lru_lock	2020-12-15 14:48:03 -08:00
page_io.c	swap: fix swapfile read/write offset	2021-03-02 17:25:46 -07:00
page_isolation.c	mm/page_isolation: do not isolate the max order page	2020-12-15 12:13:45 -08:00
page_owner.c	mm/page_owner: use helper function zone_end_pfn() to get end_pfn	2021-02-24 13:38:27 -08:00
page_poison.c	kasan, mm: reset tags when accessing metadata	2020-12-22 12:55:08 -08:00
page_reporting.c	mm/page_reporting: use list_entry_is_head() in page_reporting_cycle()	2021-02-24 13:38:30 -08:00
page_reporting.h
page_vma_mapped.c	mm/page_vma_mapped.c: add colon to fix kernel-doc markups error for check_pte	2020-12-15 12:13:41 -08:00
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c	percpu: fix clang modpost section mismatch	2021-02-14 18:15:15 +00:00
pgalloc-track.h
pgtable-generic.c	mm/pgtable-generic.c: optimize the VM_BUG_ON condition in pmdp_huge_clear_flush()	2021-02-24 13:38:30 -08:00
process_vm_access.c	mm/process_vm_access.c: include compat.h	2021-01-12 18:12:54 -08:00
ptdump.c	kasan, arm64: expand CONFIG_KASAN checks	2020-12-22 12:55:08 -08:00
readahead.c
rmap.c	mm/rmap: correct obsolete comment of page_get_anon_vma()	2021-02-26 09:41:01 -08:00
rodata_test.c
shmem.c	mm,shmem,thp: limit shmem THP allocations to requested zones	2021-02-26 09:40:59 -08:00
shuffle.c
shuffle.h
slab.c	mm, kfence: insert KFENCE hooks for SLAB	2021-02-26 09:41:02 -08:00
slab.h	mm: memcg/slab: pre-allocate obj_cgroups for slab caches with SLAB_ACCOUNT	2021-02-24 13:38:29 -08:00
slab_common.c	kasan, mm: optimize krealloc poisoning	2021-02-26 09:41:03 -08:00
slob.c	mm, tracing: record slab name for kmem_cache_free()	2021-02-24 13:38:26 -08:00
slub.c	Revert "mm, slub: consider rest of partial list if acquire_slab() fails"	2021-03-10 10:18:04 -08:00
sparse-vmemmap.c
sparse.c
swap.c	mm: remove pagevec_lookup_entries	2021-02-26 09:40:59 -08:00
swap_cgroup.c
swap_slots.c	mm/swap_slots.c: remove redundant NULL check	2021-02-24 13:38:28 -08:00
swap_state.c	mm: add FGP_ENTRY	2021-02-26 09:40:59 -08:00
swapfile.c	swap: fix swapfile read/write offset	2021-03-02 17:25:46 -07:00
truncate.c	mm: remove pagevec_lookup_entries	2021-02-26 09:40:59 -08:00
usercopy.c
userfaultfd.c
util.c	mm: Make mem_dump_obj() handle vmalloc() memory	2021-01-22 15:24:04 -08:00
vmacache.c
vmalloc.c	Merge branch 'for-mingo-rcu' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu	2021-02-12 12:56:55 +01:00
vmpressure.c
vmscan.c	mm/vmscan: restore zone_reclaim_mode ABI	2021-02-24 13:38:34 -08:00
vmstat.c	mm/vmstat.c: erase latency in vmstat_shepherd	2021-02-26 09:41:00 -08:00
workingset.c	mm: workingset: clarify eviction order and distance calculation	2021-02-24 13:38:34 -08:00
z3fold.c	mm: set the sleep_mapped to true for zbud and z3fold	2021-02-26 09:41:01 -08:00
zbud.c	mm: set the sleep_mapped to true for zbud and z3fold	2021-02-26 09:41:01 -08:00
zpool.c	mm/zswap: add the flag can_sleep_mapped	2021-02-26 09:41:01 -08:00
zsmalloc.c	mm/zsmalloc.c: use page_private() to access page->private	2021-02-26 09:41:01 -08:00
zswap.c	mm/zswap: add the flag can_sleep_mapped	2021-02-26 09:41:01 -08:00