linux/Documentation/vm
Cyrill Gorcunov d9104d1ca9 mm: track vma changes with VM_SOFTDIRTY bit
Pavel reported that in case if vma area get unmapped and then mapped (or
expanded) in-place, the soft dirty tracker won't be able to recognize this
situation since it works on pte level and ptes are get zapped on unmap,
loosing soft dirty bit of course.

So to resolve this situation we need to track actions on vma level, there
VM_SOFTDIRTY flag comes in.  When new vma area created (or old expanded)
we set this bit, and keep it here until application calls for clearing
soft dirty bit.

Thus when user space application track memory changes now it can detect if
vma area is renewed.

Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:57:56 -07:00
..
.gitignore
00-INDEX
active_mm.txt
balance
cleancache.txt
frontswap.txt
highmem.txt
hugetlbpage.txt hugepage: mention libhugetlbfs in doc 2013-09-11 15:57:39 -07:00
hwpoison.txt
ksm.txt
locking
numa
numa_memory_policy.txt
overcommit-accounting
page_migration
pagemap.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-07-04 11:40:58 -07:00
slub.txt
soft-dirty.txt mm: track vma changes with VM_SOFTDIRTY bit 2013-09-11 15:57:56 -07:00
transhuge.txt mm/thp: fix doc for transparent huge zero page 2013-07-09 10:33:23 -07:00
unevictable-lru.txt
zswap.txt zswap: add documentation 2013-07-10 18:11:34 -07:00