linux-stable.git/mm/memory.c, branch v3.11.8

mm: numa: Sanitize task_numa_fault() callsites

2013-11-13T03:08:11+00:00

commit c61109e34f60f6e85bb43c5a1cd51c0e3db40847 upstream.

There are three callers of task_numa_fault():

 - do_huge_pmd_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_pmd_numa_page():
     Accounts not at all when the page isn't migrated, otherwise
     accounts against the node we migrated towards.

This seems wrong to me; all three sites should have the same
sementaics, furthermore we should accounts against where the page
really is, we already know where the task is.

So modify all three sites to always account; we did after all receive
the fault; and always account to where the page is after migration,
regardless of success.

They all still differ on when they clear the PTE/PMD; ideally that
would get sorted too.

Signed-off-by: Mel Gorman 
Reviewed-by: Rik van Riel 
Cc: Andrea Arcangeli 
Cc: Johannes Weiner 
Cc: Srikar Dronamraju 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

mm: make generic_access_phys available for modules

2013-11-13T03:08:10+00:00

commit 5a73633ef01cd8772defa6a3c34a588376a1df4c upstream.

In the next commit this function will be used in the uio subsystem

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman

mm: migration: do not lose soft dirty bit if page is in migration state

2013-11-04T12:35:20+00:00

commit c3d16e16522fe3fe8759735850a0676da18f4b1d upstream.

If page migration is turned on in config and the page is migrating, we
may lose the soft dirty bit.  If fork and mprotect are called on
migrating pages (once migration is complete) pages do not obtain the
soft dirty bit in the correspond pte entries.  Fix it adding an
appropriate test on swap entries.

Signed-off-by: Cyrill Gorcunov 
Cc: Pavel Emelyanov 
Cc: Andy Lutomirski 
Cc: Matt Mackall 
Cc: Xiao Guangrong 
Cc: Marcelo Tosatti 
Cc: KOSAKI Motohiro 
Cc: Stephen Rothwell 
Cc: Peter Zijlstra 
Cc: "Aneesh Kumar K.V" 
Cc: Naoya Horiguchi 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Fix TLB gather virtual address range invalidation corner cases

2013-08-16T15:52:46+00:00

Ben Tebulin reported:

 "Since v3.7.2 on two independent machines a very specific Git
  repository fails in 9/10 cases on git-fsck due to an SHA1/memory
  failures.  This only occurs on a very specific repository and can be
  reproduced stably on two independent laptops.  Git mailing list ran
  out of ideas and for me this looks like some very exotic kernel issue"

and bisected the failure to the backport of commit 53a59fc67f97 ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").

That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.

The real bug is that the TLB gather virtual memory range setup is subtly
buggered.  It was introduced in commit 597e1c3580b7 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.

The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB.  And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.

Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.

This makes the patch larger, but conceptually much simpler.  And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.

Ben verified that this fixes his problem.

Reported-bisected-and-tested-by: Ben Tebulin 
Build-testing-by: Stephen Rothwell 
Build-testing-by: Richard Weinberger 
Reviewed-by: Michal Hocko 
Acked-by: Peter Zijlstra 
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

mm: save soft-dirty bits on file pages

2013-08-14T00:57:48+00:00

Andy reported that if file page get reclaimed we lose the soft-dirty bit
if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get
encoded into pte entry.  Thus when #pf happens on such non-present pte
we can restore it back.

Reported-by: Andy Lutomirski 
Signed-off-by: Cyrill Gorcunov 
Acked-by: Pavel Emelyanov 
Cc: Matt Mackall 
Cc: Xiao Guangrong 
Cc: Marcelo Tosatti 
Cc: KOSAKI Motohiro 
Cc: Stephen Rothwell 
Cc: Peter Zijlstra 
Cc: "Aneesh Kumar K.V" 
Cc: Minchan Kim 
Cc: Wanpeng Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: save soft-dirty bits on swapped pages

2013-08-14T00:57:47+00:00

Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set
get swapped out, the bit is getting lost and no longer available when
pte read back.

To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in
pte entry for the page being swapped out.  When such page is to be read
back from a swap cache we check for bit presence and if it's there we
clear it and restore the former _PAGE_SOFT_DIRTY bit back.

One of the problem was to find a place in pte entry where we can save
the _PTE_SWP_SOFT_DIRTY bit while page is in swap.  The _PAGE_PSE was
chosen for that, it doesn't intersect with swap entry format stored in
pte.

Reported-by: Andy Lutomirski 
Signed-off-by: Cyrill Gorcunov 
Acked-by: Pavel Emelyanov 
Cc: Matt Mackall 
Cc: Xiao Guangrong 
Cc: Marcelo Tosatti 
Cc: KOSAKI Motohiro 
Cc: Stephen Rothwell 
Cc: Peter Zijlstra 
Cc: "Aneesh Kumar K.V" 
Reviewed-by: Minchan Kim 
Reviewed-by: Wanpeng Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove unused VM_ macros and expand other in-place

2013-07-09T17:33:23+00:00

These VM_ macros aren't used very often and three of them
aren't used at all.

Expand the ones that are used in-place, and remove all the now unused
#define VM_ macros.

VM_READHINTMASK, VM_NormalReadHint and VM_ClearReadHint were added just
before 2.4 and appears have never been used.

Signed-off-by: Joe Perches 
Acked-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: kill global variable num_physpages

2013-07-03T23:07:38+00:00

Now all references to num_physpages have been removed, so kill it.

Signed-off-by: Jiang Liu 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Rik van Riel 
Cc: Jiang Liu 
Cc: Hugh Dickins 
Cc: David Rientjes 
Cc: Al Viro 
Cc: Konstantin Khlebnikov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix the TLB range flushed when __tlb_remove_page() runs out of slots

2013-07-03T23:07:34+00:00

zap_pte_range loops from @addr to @end.  In the middle, if it runs out of
batching slots, TLB entries needs to be flushed for @start to @interim,
NOT @interim to @end.

Since ARC port doesn't use page free batching I can't test it myself but
this seems like the right thing to do.

Observed this when working on a fix for the issue at thread:
http://www.spinics.net/lists/linux-arch/msg21736.html

Signed-off-by: Vineet Gupta 
Cc: Mel Gorman 
Cc: Hugh Dickins 
Cc: Rik van Riel 
Cc: David Rientjes 
Cc: Peter Zijlstra 
Acked-by: Catalin Marinas 
Cc: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT

2013-07-03T23:07:26+00:00

(*->vm_end - *->vm_start) >> PAGE_SHIFT operation is implemented
as a inline funcion vma_pages() in linux/mm.h, so using it.

Signed-off-by: Libin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds