kernel_optimize_test/mm
Nadav Amit 40bc831ab5 hugetlbfs: flush TLBs correctly after huge_pmd_unshare
commit a4a118f2eead1d6c49e00765de89878288d4b890 upstream.

When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB
flush is missing.  This TLB flush must be performed before releasing the
i_mmap_rwsem, in order to prevent an unshared PMDs page from being
released and reused before the TLB flush took place.

Arguably, a comprehensive solution would use mmu_gather interface to
batch the TLB flushes and the PMDs page release, however it is not an
easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call
huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2)
deferring the release of the page reference for the PMDs page until
after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into
thinking PMDs are shared when they are not.

Fix __unmap_hugepage_range() by adding the missing TLB flush, and
forcing a flush when unshare is successful.

Fixes: 24669e5847 ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:39:21 +01:00
..
kasan
backing-dev.c
balloon_compaction.c
cleancache.c
cma_debug.c
cma.c
cma.h
compaction.c
debug_page_ref.c
debug_vm_pgtable.c
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup_benchmark.c
gup.c
highmem.c
hmm.c
huge_memory.c
hugetlb_cgroup.c
hugetlb.c hugetlbfs: flush TLBs correctly after huge_pmd_unshare 2021-11-26 10:39:21 +01:00
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
ioremap.c
Kconfig
Kconfig.debug
khugepaged.c mm: khugepaged: skip huge page collapse for special files 2021-11-06 14:10:09 +01:00
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
mapping_dirty_helpers.c
memblock.c
memcontrol.c memcg: prohibit unconditional exceeding the limit of dying tasks 2021-11-18 14:04:29 +01:00
memfd.c
memory_hotplug.c mm/memory_hotplug: use "unsigned long" for PFN in zone_for_pfn_range() 2021-09-22 12:27:59 +02:00
memory-failure.c
memory.c
mempolicy.c
mempool.c
memremap.c
memtest.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c mm, oom: do not trigger out_of_memory from the #PF 2021-11-18 14:04:30 +01:00
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_vma_mapped.c
page-writeback.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c
rmap.c
rodata_test.c
shmem.c
shuffle.c
shuffle.h
slab_common.c
slab.c
slab.h mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag 2021-11-26 10:39:19 +01:00
slob.c
slub.c mm, slub: fix incorrect memcg slab count for bulk free 2021-10-27 09:56:53 +02:00
sparse-vmemmap.c
sparse.c
swap_cgroup.c
swap_slots.c
swap_state.c
swap.c
swapfile.c
truncate.c
usercopy.c
userfaultfd.c
util.c mm: don't allow oversized kvmalloc() calls 2021-10-06 15:56:03 +02:00
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c mm,vmscan: fix divide by zero in get_scan_count 2021-09-18 13:40:36 +02:00
vmstat.c
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c mm/zsmalloc.c: close race window between zs_pool_dec_isolated() and zs_unregister_migration() 2021-11-18 14:04:26 +01:00
zswap.c