Commit Graph

24042 Commits

Author SHA1 Message Date
Mel Gorman
8afdcece49 mm: vmscan: kswapd should not free an excessive number of pages when balancing small zones
When reclaiming for order-0 pages, kswapd requires that all zones be
balanced.  Each cycle through balance_pgdat() does background ageing on
all zones if necessary and applies equal pressure on the inactive zone
unless a lot of pages are free already.

A "lot of free pages" is defined as a "balance gap" above the high
watermark which is currently 7*high_watermark.  Historically this was
reasonable as min_free_kbytes was small.  However, on systems using huge
pages, it is recommended that min_free_kbytes is higher and it is tuned
with hugeadm --set-recommended-min_free_kbytes.  With the introduction of
transparent huge page support, this recommended value is also applied.  On
X86-64 with 4G of memory, min_free_kbytes becomes 67584 so one would
expect around 68M of memory to be free.  The Normal zone is approximately
35000 pages so under even normal memory pressure such as copying a large
file, it gets exhausted quickly.  As it is getting exhausted, kswapd
applies pressure equally to all zones, including the DMA32 zone.  DMA32 is
approximately 700,000 pages with a high watermark of around 23,000 pages.
In this situation, kswapd will reclaim around (23000*8 where 8 is the high
watermark + balance gap of 7 * high watermark) pages or 718M of pages
before the zone is ignored.  What the user sees is that free memory far
higher than it should be.

To avoid an excessive number of pages being reclaimed from the larger
zones, explicitely defines the "balance gap" to be either 1% of the zone
or the low watermark for the zone, whichever is smaller.  While kswapd
will check all zones to apply pressure, it'll ignore zones that meets the
(high_wmark + balance_gap) watermark.

To test this, 80G were copied from a partition and the amount of memory
being used was recorded.  A comparison of a patch and unpatched kernel can
be seen at
http://www.csn.ul.ie/~mel/postings/minfree-20110222/memory-usage-hydra.ps
and shows that kswapd is not reclaiming as much memory with the patch
applied.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:04 -07:00
Dave Hansen
033193275b pagewalk: only split huge pages when necessary
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will
unconditionally split any transparent huge pages it runs in to.  In
practice, that means that anyone doing a

	cat /proc/$pid/smaps

will unconditionally break down every huge page in the process and depend
on khugepaged to re-collapse it later.  This is fairly suboptimal.

This patch changes that behavior.  It teaches each ->pmd_entry handler
(there are five) that they must break down the THPs themselves.  Also, the
_generic_ code will never break down a THP unless a ->pte_entry handler is
actually set.

This means that the ->pmd_entry handlers can now choose to deal with THPs
without breaking them down.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:04 -07:00
Minchan Kim
3f58a82943 memcg: move memcg reclaimable page into tail of inactive list
The rotate_reclaimable_page function moves just written out pages, which
the VM wanted to reclaim, to the end of the inactive list.  That way the
VM will find those pages first next time it needs to free memory.

This patch applies the rule in memcg.  It can help to prevent unnecessary
working page eviction of memcg.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Minchan Kim
315601809d mm: deactivate invalidated pages
Recently, there are reported problem about thrashing.
(http://marc.info/?l=rsync&m=128885034930933&w=2) It happens by backup
workloads(ex, nightly rsync).  That's because the workload makes just
use-once pages and touches pages twice.  It promotes the page into active
list so that it results in working set page eviction.

Some app developer want to support POSIX_FADV_NOREUSE.  But other OSes
don't support it, either.
(http://marc.info/?l=linux-mm&m=128928979512086&w=2)

By other approach, app developers use POSIX_FADV_DONTNEED.  But it has a
problem.  If kernel meets page is writing during invalidate_mapping_pages,
it can't work.  It makes for application programmer to use it since they
always have to sync data before calling fadivse(..POSIX_FADV_DONTNEED) to
make sure the pages could be discardable.  At last, they can't use
deferred write of kernel so that they could see performance loss.
(http://insights.oetiker.ch/linux/fadvise.html)

In fact, invalidation is very big hint to reclaimer.  It means we don't
use the page any more.  So let's move the writing page into inactive
list's head if we can't truncate it right now.

Why I move page to head of lru on this patch, Dirty/Writeback page would
be flushed sooner or later.  It can prevent writeout of pageout which is
less effective than flusher's writeout.

Originally, I reused lru_demote of Peter with some change so added his
Signed-off-by.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reported-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Richard Kennedy
481b4bb5e3 mm: mm_struct: remove 16 bytes of alignment padding on 64 bit builds
Reorder mm_struct to remove 16 bytes of alignment padding on 64 bit
builds.  On my config this shrinks mm_struct by enough to fit in one
fewer cache lines and allows more objects per slab in mm_struct
kmem_cache under SLUB.

slabinfo before patch :-
    Sizes (bytes)     Slabs
    --------------------------------
    Object :     848  Total  :       9
    SlabObj:     896  Full   :       2
    SlabSiz:   16384  Partial:       5
    Loss   :      48  CpuSlab:       2
    Align  :      64  Objects:      18

 slabinfo after :-
    Sizes (bytes)     Slabs
    --------------------------------
    Object :     832  Total  :       7
    SlabObj:     832  Full   :       2
    SlabSiz:   16384  Partial:       3
    Loss   :       0  CpuSlab:       2
    Align  :      64  Objects:      19

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Michel Lespinasse
cb240452bf mm: remove unused TestSetPageLocked() interface
TestSetPageLocked() isn't being used anywhere.  Also, using it would
likely be an error, since the proper interface trylock_page() provides
stronger ordering guarantees.

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Peter Zijlstra
01d8b20dec mm: simplify anon_vma refcounts
This patch changes the anon_vma refcount to be 0 when the object is free.
It does this by adding 1 ref to being in use in the anon_vma structure
(iow.  the anon_vma->head list is not empty).

This allows a simpler release scheme without having to check both the
refcount and the list as well as avoids taking a ref for each entry on the
list.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Peter Zijlstra
83813267c6 mm: move anon_vma ref out from under CONFIG_foo
We need the anon_vma refcount unconditionally to simplify the anon_vma
lifetime rules.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Peter Zijlstra
9e60109f12 mm: rename drop_anon_vma() to put_anon_vma()
The normal code pattern used in the kernel is: get/put.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:03 -07:00
Minchan Kim
e64a782fec mm: change __remove_from_page_cache()
Now we renamed remove_from_page_cache with delete_from_page_cache.  As
consistency of __remove_from_swap_cache and remove_from_swap_cache, we
change internal page cache handling function name, too.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
Minchan Kim
702cfbf93a mm: goodbye remove_from_page_cache()
Now delete_from_page_cache() replaces remove_from_page_cache().  So we
remove remove_from_page_cache so fs or something out of mainline will
notice it when compile time and can fix it.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
Minchan Kim
97cecb5a25 mm: introduce delete_from_page_cache()
Presently we increase the page refcount in add_to_page_cache() but don't
decrease it in remove_from_page_cache().  Such asymmetry adds confusion,
requiring that callers notice it and a comment explaining why they release
a page reference.  It's not a good API.

A long time ago, Hugh tried it (http://lkml.org/lkml/2004/10/24/140) but
gave up because reiser4's drop_page() had to unlock the page between
removing it from page cache and doing the page_cache_release().  But now
the situation is changed.  I think at least things in current mainline
don't have any obstacles.  The problem is for out-of-mainline filesystems
- if they have done such things as reiser4, this patch could be a problem
but they will discover this at compile time since we remove
remove_from_page_cache().

This patch:

This function works as just wrapper remove_from_page_cache().  The
difference is that it decreases page references in itself.  So caller have
to make sure it has a page reference before calling.

This patch is ready for removing remove_from_page_cache().

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Edward Shishkin <edward.shishkin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
Miklos Szeredi
ef6a3c6311 mm: add replace_page_cache_page() function
This function basically does:

     remove_from_page_cache(old);
     page_cache_release(old);
     add_to_page_cache_locked(new);

Except it does this atomically, so there's no possibility for the "add" to
fail because of a race.

If memory cgroups are enabled, then the memory cgroup charge is also moved
from the old page to the new.

This function is currently used by fuse to move pages into the page cache
on read, instead of copying the page contents.

[minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
Gleb Natapov
318b275fbc mm: allow GUP to fail instead of waiting on a page
GUP user may want to try to acquire a reference to a page if it is already
in memory, but not if IO, to bring it in, is needed.  For example KVM may
tell vcpu to schedule another guest process if current one is trying to
access swapped out page.  Meanwhile, the page will be swapped in and the
guest process, that depends on it, will be able to run again.

This patch adds FAULT_FLAG_RETRY_NOWAIT (suggested by Linus) and
FOLL_NOWAIT follow_page flags.  FAULT_FLAG_RETRY_NOWAIT, when used in
conjunction with VM_FAULT_ALLOW_RETRY, indicates to handle_mm_fault that
it shouldn't drop mmap_sem and wait on a page, but return VM_FAULT_RETRY
instead.

[akpm@linux-foundation.org: improve FOLL_NOWAIT comment]
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
David Rientjes
ddd588b5dd oom: suppress nodes that are not allowed from meminfo on oom kill
The oom killer is extremely verbose for machines with a large number of
cpus and/or nodes.  This verbosity can often be harmful if it causes other
important messages to be scrolled from the kernel log and incurs a
signicant time delay, specifically for kernels with CONFIG_NODES_SHIFT >
8.

This patch causes only memory information to be displayed for nodes that
are allowed by current's cpuset when dumping the VM state.  Information
for all other nodes is irrelevant to the oom condition; we don't care if
there's an abundance of memory elsewhere if we can't access it.

This only affects the behavior of dumping memory information when an oom
is triggered.  Other dumps, such as for sysrq+m, still display the
unfiltered form when using the existing show_mem() interface.

Additionally, the per-cpu pageset statistics are extremely verbose in oom
killer output, so it is now suppressed.  This removes

	nodes_weight(current->mems_allowed) * (1 + nr_cpus)

lines from the oom killer output.

Callers may use __show_mem(SHOW_MEM_FILTER_NODES) to filter disallowed
nodes.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:01 -07:00
Eric Dumazet
207205a2ba kthread: NUMA aware kthread_create_on_node()
All kthreads being created from a single helper task, they all use memory
from a single node for their kernel stack and task struct.

This patch suite creates kthread_create_on_node(), adding a 'cpu' parameter
to parameters already used by kthread_create().

This parameter serves in allocating memory for the new kthread on its
memory node if possible.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:01 -07:00
Andrea Arcangeli
d527caf22e mm: compaction: prevent kswapd compacting memory to reduce CPU usage
This patch reverts 5a03b051 ("thp: use compaction in kswapd for GFP_ATOMIC
order > 0") due to reports stating that kswapd CPU usage was higher and
IRQs were being disabled more frequently.  This was reported at
http://www.spinics.net/linux/fedora/alsa-user/msg09885.html.

Without this patch applied, CPU usage by kswapd hovers around the 20% mark
according to the tester (Arthur Marsh:
http://www.spinics.net/linux/fedora/alsa-user/msg09899.html).  With this
patch applied, it's around 2%.

The problem is not related to THP which specifies __GFP_NO_KSWAPD but is
triggered by high-order allocations hitting the low watermark for their
order and waking kswapd on kernels with CONFIG_COMPACTION set.  The most
common trigger for this is network cards configured for jumbo frames but
it's also possible it'll be triggered by fork-heavy workloads (order-1)
and some wireless cards which depend on order-1 allocations.

The symptoms for the user will be high CPU usage by kswapd in low-memory
situations which could be confused with another writeback problem.  While
a patch like 5a03b051 may be reintroduced in the future, this patch plays
it safe for now and reverts it.

[mel@csn.ul.ie: Beefed up the changelog]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Tested-by: Arthur Marsh <arthur.marsh@internode.on.net>
Cc: <stable@kernel.org>		[2.6.38.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:00 -07:00
Robert Morell
ef0a5e80f5 pwm_backlight: add check_fb() hook
In systems with multiple framebuffer devices, one of the devices might be
blanked while another is unblanked.  In order for the backlight blanking
logic to know whether to turn off the backlight for a particular
framebuffer's blanking notification, it needs to be able to check if a
given framebuffer device corresponds to the backlight.

This plumbs the check_fb hook from core backlight through the
pwm_backlight helper to allow platform code to plug in a check_fb hook.

Signed-off-by: Robert Morell <rmorell@nvidia.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Arun Murthy <arun.murthy@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:00 -07:00
Matthew Garrett
bb7ca747f8 backlight: add backlight type
There may be multiple ways of controlling the backlight on a given
machine.  Allow drivers to expose the type of interface they are
providing, making it possible for userspace to make appropriate policy
decisions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:43:59 -07:00
Uwe Kleine-König
9517f925f2 leds: make *struct gpio_led_platform_data.leds const
And fix a typo.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:43:59 -07:00
Shreshtha Kumar Sahu
b1e6b7068f leds: add driver for LM3530 ALS
Simple backlight driver for National Semiconductor LM3530.  Presently only
manual mode is supported, PWM and ALS support to be added.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:43:59 -07:00
Linus Torvalds
01ba825146 Merge branch 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Add statistics for this_cmpxchg_double failures
  slub: Add missing irq restore for the OOM path
2011-03-22 16:26:57 -07:00
Linus Torvalds
0adfc56ce8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: use watch/notify for changes in rbd header
  libceph: add lingering request and watch/notify event framework
  rbd: update email address in Documentation
  ceph: rename dentry_release -> d_release, fix comment
  ceph: add request to the tail of unsafe write list
  ceph: remove request from unsafe list if it is canceled/timed out
  ceph: move readahead default to fs/ceph from libceph
  ceph: add ino32 mount option
  ceph: update common header files
  ceph: remove debugfs debug cruft
  libceph: fix osd request queuing on osdmap updates
  ceph: preserve I_COMPLETE across rename
  libceph: Fix base64-decoding when input ends in newline.
2011-03-22 16:25:25 -07:00
Linus Torvalds
f23eb2b2b2 tty: stop using "delayed_work" in the tty layer
Using delayed-work for tty flip buffers ends up causing us to wait for
the next tick to complete some actions.  That's usually not all that
noticeable, but for certain latency-critical workloads it ends up being
totally unacceptable.

As an extreme case of this, passing a token back-and-forth over a pty
will take two ticks per iteration, so even just a thousand iterations
will take 8 seconds assuming a common 250Hz configuration.

Avoiding the whole delayed work issue brings that ping-pong test-case
down to 0.009s on my machine.

In more practical terms, this latency has been a performance problem for
things like dive computer simulators (simulating the serial interface
using the ptys) and for other environments (Alan mentions a CP/M emulator).

Reported-by: Jef Driesen <jefdriesen@telenet.be>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 16:17:32 -07:00
Christoph Lameter
4fdccdfbb4 slub: Add statistics for this_cmpxchg_double failures
Add some statistics for debugging.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-22 20:48:04 +02:00
Yehuda Sadeh
a40c4f10e3 libceph: add lingering request and watch/notify event framework
Lingering requests are requests that are sent to the OSD normally but
tracked also after we get a successful request.  This keeps the OSD
connection open and resends the original request if the object moves to
another OSD.  The OSD can then send notification messages back to us
if another client initiates a notify.

This framework will be used by RBD so that the client gets notification
when a snapshot is created by another node or tool.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-03-22 11:33:55 -07:00
Linus Torvalds
75ea6358bc Merge branch 'for-linus/2639/i2c-2' of git://git.fluff.org/bjdooks/linux
* 'for-linus/2639/i2c-2' of git://git.fluff.org/bjdooks/linux:
  i2c-pxa2xx: Don't clear isr bits too early
  i2c-pxa2xx: Fix register offsets
  i2c-pxa2xx: pass of_node from platform driver to adapter and publish
  i2c-pxa2xx: check timeout correctly
  i2c-pxa2xx: add support for shared IRQ handler
  i2c-pxa2xx: Add PCI support for PXA I2C controller
  ARM: pxa2xx: reorganize I2C files
  i2c-pxa2xx: use dynamic register layout
  i2c-mxs: set controller to pio queue mode after reset
  i2c-eg20t: support new device OKI SEMICONDUCTOR ML7213 IOH
  i2c/busses: Add support for Diolan U2C-12 USB-I2C adapter
2011-03-22 10:05:27 -07:00
Linus Torvalds
14577beb82 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Dont define useless label in the !CONFIG_CMPXCHG_LOCAL case
  slab,rcu: don't assume the size of struct rcu_head
  slub,rcu: don't assume the size of struct rcu_head
  slub: automatically reserve bytes at the end of slab
  Lockless (and preemptless) fastpaths for slub
  slub: Get rid of slab_free_hook_irq()
  slub: min_partial needs to be in first cacheline
  slub: fix ksize() build error
  slub: fix kmemcheck calls to match ksize() hints
  Revert "slab: Fix missing DEBUG_SLAB last user"
  mm: Remove support for kmem_cache_name()
2011-03-22 09:36:23 -07:00
Linus Torvalds
c62b389863 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (33 commits)
  IPVS: Use global mutex in ip_vs_app.c
  ipvs: fix a typo in __ip_vs_control_init()
  veth: Fix the byte counters
  net ipv6: Fix duplicate /proc/sys/net/ipv6/neigh directory entries.
  macvlan: Fix use after free of struct macvlan_port.
  net: fix incorrect spelling in drop monitor protocol
  can: c_can: Do basic c_can configuration _before_ enabling the interrupts
  net/appletalk: fix atalk_release use after free
  ipx: fix ipx_release()
  snmp: SNMP_UPD_PO_STATS_BH() always called from softirq
  l2tp: fix possible oops on l2tp_eth module unload
  xfrm: Fix initialize repl field of struct xfrm_state
  netfilter: ipt_CLUSTERIP: fix buffer overflow
  netfilter: xtables: fix reentrancy
  netfilter: ipset: fix checking the type revision at create command
  netfilter: ipset: fix address ranges at hash:*port* types
  niu: Rename NIU parent platform device name to fix conflict.
  r8169: fix a bug in rtl8169_init_phy()
  bonding: fix a typo in a comment
  ftmac100: use resource_size()
  ...
2011-03-22 09:25:34 -07:00
Linus Torvalds
afd8c40431 Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (ads1015) Make gain and datarate configurable
  hwmon: (ads1015) Drop dynamic attribute group
  hwmon: Add support for Texas Instruments ADS1015
  hwmon: New driver for SMSC SCH5627
  hwmon: (abituguru*) Update my email address
  hwmon: (lm75) Speed up detection
  hwmon: (lm75) Add detection of the National Semiconductor LM75A
  hp_accel: Fix driver name
  Move lis3lv02d drivers to drivers/misc
  Move hp_accel to drivers/platform/x86
  Let Kconfig handle lis3lv02d dependencies
  hwmon: (sht15) Fix integer overflow in humidity calculation
  hwmon: (sht15) Spelling fix
  hwmon: (w83795) Document pin mapping
2011-03-21 14:02:55 -07:00
Sage Weil
80456f8672 ceph: move readahead default to fs/ceph from libceph
Signed-off-by: Sage Weil <sage@newdream.net>
2011-03-21 12:24:23 -07:00
Yehuda Sadeh
483fac7148 ceph: update common header files
This updates the common header files used by the different ceph
related modules. Specifically it adds definitions required by
the rbd watch/notify feature.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
2011-03-21 12:24:21 -07:00
Sage Weil
6f6c700675 libceph: fix osd request queuing on osdmap updates
If we send a request to osd A, and the request's pg remaps to osd B and
then back to A in quick succession, we need to resend the request to A. The
old code was only calling kick_requests after processing all incremental
maps in a message, so it was very possible to not resend a request that
needed to be resent.  This would make the osd eventually time out (at least
with the current default of osd timeouts enabled).

The correct approach is to scan requests on every map incremental.  This
patch refactors the kick code in a few ways:
 - all requests are either on req_lru (in flight), req_unsent (ready to
   send), or req_notarget (currently map to no up osd)
 - mapping always done by map_request (previous map_osds)
 - if the mapping changes, we requeue.  requests are resent only after all
   map incrementals are processed.
 - some osd reset code is moved out of kick_requests into a separate
   function
 - the "kick this osd" functionality is moved to kick_osd_requests, as it
   is unrelated to scanning for request->pg->osd mapping changes

Signed-off-by: Sage Weil <sage@newdream.net>
2011-03-21 12:24:19 -07:00
Linus Torvalds
10effcb548 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  FS: lookup_mnt() is only used in the core fs routines now
  bfs: fix bitmap size argument to find_first_zero_bit()
  fs: Use BUG_ON(!mnt) at dentry_open().
  fs: devpts_pty_new() return -ENOMEM if dentry allocation failed
  nfs: lock() vs unlock() typo
  pstore: fix leaking ->i_private
  introduce sys_syncfs to sync a single file system
  Small typo fix...
  Filesystem: fifo: Fixed coding style issue.
  fs/inode: Fix kernel-doc format for inode_init_owner
  select: remove unused MAX_SELECT_SECONDS
  vfs: cleanup do_vfs_ioctl()
2011-03-21 10:06:51 -07:00
Linus Torvalds
c3ca48f062 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: core: ignore link-active bit of new nodes, fix device recognition
  firewire: sbp2: revert obsolete 'fix stall with "Unsolicited response"'
  firewire: core: increase default SPLIT_TIMEOUT value
  firewire: ohci: Misleading kfree in ohci.c::pci_probe/remove
  firewire: ohci: omit IntEvent.busReset check rom AT queueing
  firewire: ohci: prevent starting of iso contexts with empty queue
  firewire: ohci: prevent iso completion callbacks after context stop
  firewire: core: rename some variables
  firewire: nosy: should work on Power Mac G4 PCI too
  firewire: core: fix card->reset_jiffies overflow
  firewire: cdev: remove unneeded reference
  firewire: cdev: always wait for outbound transactions to complete
  firewire: cdev: remove unneeded idr_find() from complete_transaction()
  firewire: ohci: log dead DMA contexts
2011-03-21 10:05:22 -07:00
Dirk Eibach
c0046867f3 hwmon: (ads1015) Make gain and datarate configurable
Configuration for ads1015 gain and datarate is possible via
devicetree or platform data.

This is a followup patch to previous ads1015 patches on Jean Delvares
tree.

Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-21 17:59:37 +01:00
Dirk Eibach
8c22a8f575 hwmon: Add support for Texas Instruments ADS1015
Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-21 17:59:36 +01:00
David Howells
0f60f240d5 FS: lookup_mnt() is only used in the core fs routines now
lookup_mnt() is only used in the core fs routines now, so it doesn't need to
be globally declared anymore.  It isn't exported to modules at the moment, so
nothing that can be modularised seems to be using it.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-21 12:13:10 -04:00
Sebastian Andrzej Siewior
b459396ee9 ARM: pxa2xx: reorganize I2C files
This patch moves the platform data definition from
arch/arm/plat-pxa/include/plat/i2c.h to include/linux/i2c/pxa-i2c.h so
it can be accessed from x86 the same way as on ARM.

This change should make no functional change to the PXA code. The move
is verified by building the following defconfigs:
  cm_x2xx_defconfig corgi_defconfig em_x270_defconfig ezx_defconfig
  imote2_defconfig pxa3xx_defconfig spitz_defconfig zeus_defconfig
  raumfeld_defconfig magician_defconfig mmp2_defconfig pxa168_defconfig
  pxa910_defconfig

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-03-21 09:09:33 +00:00
Sage Weil
b7ed78f565 introduce sys_syncfs to sync a single file system
It is frequently useful to sync a single file system, instead of all
mounted file systems via sync(2):

 - On machines with many mounts, it is not at all uncommon for some of
   them to hang (e.g. unresponsive NFS server).  sync(2) will get stuck on
   those and may never get to the one you do care about (e.g., /).
 - Some applications write lots of data to the file system and then
   want to make sure it is flushed to disk.  Calling fsync(2) on each
   file introduces unnecessary ordering constraints that result in a large
   amount of sub-optimal writeback/flush/commit behavior by the file
   system.

There are currently two ways (that I know of) to sync a single super_block:

 - BLKFLSBUF ioctl on the block device: That also invalidates the bdev
   mapping, which isn't usually desirable, and doesn't work for non-block
   file systems.
 - 'mount -o remount,rw' will call sync_filesystem as an artifact of the
   current implemention.  Relying on this little-known side effect for
   something like data safety sounds foolish.

Both of these approaches require root privileges, which some applications
do not have (nor should they need?) given that sync(2) is an unprivileged
operation.

This patch introduces a new system call syncfs(2) that takes an fd and
syncs only the file system it references.  Maybe someday we can

 $ sync /some/path

and not get

 sync: ignoring all arguments

The syscall is motivated by comments by Al and Christoph at the last LSF.
syncfs(2) seems like an appropriate name given statfs(2).

A similar ioctl was also proposed a while back, see
	http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-21 00:40:29 -04:00
Pekka Enberg
e8c500c2b6 Merge branch 'slub/lockless' into for-linus
Conflicts:
	include/linux/slub_def.h
2011-03-20 18:13:26 +02:00
Pekka Enberg
c53badd080 Merge branch 'slab/next' into for-linus 2011-03-20 18:12:03 +02:00
Jozsef Kadlecsik
5e0c1eb7e6 netfilter: ipset: fix address ranges at hash:*port* types
The hash:*port* types with IPv4 silently ignored when address ranges
with non TCP/UDP were added/deleted from the set and used the first
address from the range only.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-03-20 15:33:26 +01:00
Jean Delvare
c185a9420b i2c: Drop i2c_adapter.id
There is no user left of i2c_adapter.id, so we can get rid of it.
Finally! :)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:53 +01:00
Jean Delvare
fe6fc25857 i2c: Deprecate i2c_driver.attach_adapter and .detach_adapter
The last legitimate user of i2c_driver.attach_adapter and
.detach_adapter is gone, so we can finally deprecate these callbacks.
The last few drivers which still use these will have to be updated to
make use of standard I2C device instantiation ways instead.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:53 +01:00
Jean Delvare
7ae31482a8 i2c: Export i2c_for_each_dev
Introduce i2c_for_each_dev(), an i2c device iterator with proper
locking for use by i2c-dev. This is needed so that we can get rid of
the attach_adapter and detach_adapter legacy callback functions.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Jean Delvare
0c31f8e572 i2c: Get rid of <linux/i2c-id.h>
The last remaining ID in <linux/i2c-id.h> is no longer used anywhere,
so we can finally get rid of it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Jean Delvare
d735b34db3 i2c: make i2c_get_adapter prototype clearer
Rename the parameter of i2c_get_adapter() to "nr", to make it clear we
are passing an adapter number and not an adapter ID (which have gone
away by now.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Linus Torvalds
a952baa034 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (64 commits)
  Input: tsc2005 - remove 'disable' sysfs attribute
  Input: tsc2005 - add open/close
  Input: tsc2005 - handle read errors from SPI layer
  Input: tsc2005 - do not rearm timer in hardirq handler
  Input: tsc2005 - don't use work for 'pen up' handling
  Input: tsc2005 - do not use 0 in place of NULL
  Input: tsc2005 - use true/false for boolean variables
  Input: tsc2005 - hide selftest attribute if we can't reset
  Input: tsc2005 - rework driver initialization code
  Input: tsc2005 - set up bus type in input device
  Input: tsc2005 - set up parent device
  Input: tsc2005 - clear driver data after unbinding
  Input: tsc2005 - add module description
  Input: tsc2005 - remove driver banner message
  Input: tsc2005 - remove incorrect module alias
  Input: tsc2005 - convert to using dev_pm_ops
  Input: tsc2005 - use spi_get/set_drvdata()
  Input: introduce tsc2005 driver
  Input: xen-kbdfront - move to drivers/input/misc
  Input: xen-kbdfront - add grant reference for shared page
  ...
2011-03-19 22:27:06 -07:00
Dmitry Torokhov
97eb3f2435 Merge branch 'next' into for-linus 2011-03-18 23:38:50 -07:00