kernel_optimize_test/mm
Kirill A. Shutemov 8a04446ab0 mm, dax: VMA with vm_ops->pfn_mkwrite wants to be write-notified
For VM_PFNMAP and VM_MIXEDMAP we use vm_ops->pfn_mkwrite instead of
vm_ops->page_mkwrite to notify abort write access.  This means we want
vma->vm_page_prot to be write-protected if the VMA provides this vm_ops.

A theoretical scenario that will cause these missed events is:

  On writable mapping with vm_ops->pfn_mkwrite, but without
  vm_ops->page_mkwrite: read fault followed by write access to the pfn.
  Writable pte will be set up on read fault and write fault will not be
  generated.

I found it examining Dave's complaint on generic/080:

	http://lkml.kernel.org/g/20150831233803.GO3902@dastard

Although I don't think it's the reason.

It shouldn't be a problem for ext2/ext4 as they provide both pfn_mkwrite
and page_mkwrite.

[akpm@linux-foundation.org: add local vm_ops to avoid 80-cols mess]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yigal Korman <yigal@plexistor.com>
Acked-by: Boaz Harrosh <boaz@plexistor.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22 15:09:53 -07:00
..
kasan kasan: fix last shadow judgement in memory_is_poisoned_16() 2015-09-17 21:16:07 -07:00
backing-dev.c
balloon_compaction.c
bootmem.c
cleancache.c
cma_debug.c
cma.c
cma.h
compaction.c
debug-pagealloc.c
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup.c
highmem.c
huge_memory.c
hugetlb_cgroup.c
hugetlb.c
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c
memory_hotplug.c
memory-failure.c
memory.c
mempolicy.c
mempool.c
memtest.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c mm, dax: VMA with vm_ops->pfn_mkwrite wants to be write-notified 2015-09-22 15:09:53 -07:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page-writeback.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c
shmem.c
slab_common.c
slab.c
slab.h
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap_cgroup.c
swap_state.c
swap.c
swapfile.c
truncate.c
userfaultfd.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
zbud.c
zpool.c
zsmalloc.c
zswap.c