linux.git/mm/mlock.c, branch v2.6.37

mm: Move vma_stack_continue into mm.h

2010-09-09T16:05:06+00:00

So it can be used by all that need to check for that.

Signed-off-by: Stefan Bader 
Signed-off-by: Linus Torvalds

mm: make the mlock() stack guard page checks stricter

2010-08-21T15:49:50+00:00

If we've split the stack vma, only the lowest one has the guard page.
Now that we have a doubly linked list of vma's, checking this is trivial.

Tested-by: Ian Campbell 
Signed-off-by: Linus Torvalds

mm: fix up some user-visible effects of the stack guard page

2010-08-15T18:35:52+00:00

This commit makes the stack guard page somewhat less visible to user
space. It does this by:

 - not showing the guard page in /proc//maps

   It looks like lvm-tools will actually read /proc/self/maps to figure
   out where all its mappings are, and effectively do a specialized
   "mlockall()" in user space.  By not showing the guard page as part of
   the mapping (by just adding PAGE_SIZE to the start for grows-up
   pages), lvm-tools ends up not being aware of it.

 - by also teaching the _real_ mlock() functionality not to try to lock
   the guard page.

   That would just expand the mapping down to create a new guard page,
   so there really is no point in trying to lock it in place.

It would perhaps be nice to show the guard page specially in
/proc//maps (or at least mark grow-down segments some way), but
let's not open ourselves up to more breakage by user space from programs
that depends on the exact deails of the 'maps' file.

Special thanks to Henrique de Moraes Holschuh for diving into lvm-tools
source code to see what was going on with the whole new warning.

Reported-and-tested-by: François Valenduc 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

x86, perf, bts, mm: Delete the never used BTS-ptrace code

2010-03-26T10:33:55+00:00

Support for the PMU's BTS features has been upstreamed in
v2.6.32, but we still have the old and disabled ptrace-BTS,
as Linus noticed it not so long ago.

It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without
regard for other uses (perf) and doesn't provide the flexibility
needed for perf either.

Its users are ptrace-block-step and ptrace-bts, since ptrace-bts
was never used and ptrace-block-step can be implemented using a
much simpler approach.

So axe all 3000 lines of it. That includes the *locked_memory*()
APIs in mm/mlock.c as well.

Reported-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra 
Cc: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Markus Metzger 
Cc: Steven Rostedt 
Cc: Andrew Morton 
LKML-Reference: <20100325135413.938004390@chello.nl>
Signed-off-by: Ingo Molnar

mm: use rlimit helpers

2010-03-06T19:26:24+00:00

Make sure compiler won't do weird things with limits.  E.g.  fetching them
twice may return 2 different values after writable limits are implemented.

I.e.  either use rlimit helpers added in
3e10e716abf3c71bdb5d86b8f507f9e72236c9cd ("resource: add helpers for
fetching rlimits") or ACCESS_ONCE if not applicable.

Signed-off-by: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mlock: replace stale comments in munlock_vma_page()

2009-12-15T16:53:23+00:00

Cleanup stale comments on munlock_vma_page().

Signed-off-by: Lee Schermerhorn 
Acked-by: Hugh Dickins 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ksm: fix mlockfreed to munlocked

2009-12-15T16:53:19+00:00

When KSM merges an mlocked page, it has been forgetting to munlock it:
that's been left to free_page_mlock(), which reports it in /proc/vmstat as
unevictable_pgs_mlockfreed instead of unevictable_pgs_munlocked (and
whinges "Page flag mlocked set for process" in mmotm, whereas mainline is
silently forgiving).  Call munlock_vma_page() to fix that.

Signed-off-by: Hugh Dickins 
Cc: Izik Eidus 
Cc: Andrea Arcangeli 
Cc: Chris Wright 
Acked-by: Rik van Riel 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: mlocking in try_to_unmap_one

2009-12-15T16:53:17+00:00

There's contorted mlock/munlock handling in try_to_unmap_anon() and
try_to_unmap_file(), which we'd prefer not to repeat for KSM swapping.
Simplify it by moving it all down into try_to_unmap_one().

One thing is then lost, try_to_munlock()'s distinction between when no vma
holds the page mlocked, and when a vma does mlock it, but we could not get
mmap_sem to set the page flag.  But its only caller takes no interest in
that distinction (and is better testing SWAP_MLOCK anyway), so let's keep
the code simple and return SWAP_AGAIN for both cases.

try_to_unmap_file()'s TTU_MUNLOCK nonlinear handling was particularly
amusing: once unravelled, it turns out to have been choosing between two
different ways of doing the same nothing.  Ah, no, one way was actually
returning SWAP_FAIL when it meant to return SWAP_SUCCESS.

[kosaki.motohiro@jp.fujitsu.com: comment adding to mlocking in try_to_unmap_one]
[akpm@linux-foundation.org: remove test of MLOCK_PAGES]
Signed-off-by: Hugh Dickins 
Cc: Izik Eidus 
Cc: Andrea Arcangeli 
Cc: Nick Piggin 
Cc: Rik van Riel 
Cc: Lee Schermerhorn 
Cc: Andi Kleen 
Cc: KAMEZAWA Hiroyuki 
Cc: Wu Fengguang 
Cc: Minchan Kim 
Signed-off-by: KOSAKI Motohiro 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: m(un)lock avoid ZERO_PAGE

2009-09-22T14:17:40+00:00

I'm still reluctant to clutter __get_user_pages() with another flag, just
to avoid touching ZERO_PAGE count in mlock(); though we can add that later
if it shows up as an issue in practice.

But when mlocking, we can test page->mapping slightly earlier, to avoid
the potentially bouncy rescheduling of lock_page on ZERO_PAGE - mlock
didn't lock_page in olden ZERO_PAGE days, so we might have regressed.

And when munlocking, it turns out that FOLL_DUMP coincidentally does
what's needed to avoid all updates to ZERO_PAGE, so use that here also.
Plus add comment suggested by KAMEZAWA Hiroyuki.

Signed-off-by: Hugh Dickins 
Cc: Rik van Riel 
Cc: KAMEZAWA Hiroyuki 
Cc: Nick Piggin 
Acked-by: Mel Gorman 
Cc: Minchan Kim 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: FOLL flags for GUP flags

2009-09-22T14:17:40+00:00

__get_user_pages() has been taking its own GUP flags, then processing
them into FOLL flags for follow_page().  Though oddly named, the FOLL
flags are more widely used, so pass them to __get_user_pages() now.
Sorry, VM flags, VM_FAULT flags and FAULT_FLAGs are still distinct.

(The patch to __get_user_pages() looks peculiar, with both gup_flags
and foll_flags: the gup_flags remain constant; but as before there's
an exceptional case, out of scope of the patch, in which foll_flags
per page have FOLL_WRITE masked off.)

Signed-off-by: Hugh Dickins 
Cc: Rik van Riel 
Cc: KAMEZAWA Hiroyuki 
Cc: KOSAKI Motohiro 
Cc: Nick Piggin 
Cc: Mel Gorman 
Cc: Minchan Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds