Commit Graph

32172 Commits

Author SHA1 Message Date
Ingo Molnar
38130ec087 Merge tag 'sched-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull more cputime cleanups from Frederic Weisbecker:

 * Get rid of underscores polluting the vtime namespace

 * Consolidate context switch and tick handling

 * Improve debuggability by detecting irq unsafe callers

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-08 15:44:43 +01:00
Ingo Molnar
e783377e93 Merge tag 'cputime-adjustment-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core
Pull cputime cleanups from Frederic Weisbecker:

 * Improve naming and code location

 * Consolidate adjustment code

 * Comment the adjustement code

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-08 15:31:07 +01:00
Ingo Molnar
222e82bef4 Merge branch 'linus' into sched/core
Pick up the autogroups fix and other fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-07 12:15:33 +01:00
Mel Gorman
18a2f371f5 tmpfs: fix shared mempolicy leak
This fixes a regression in 3.7-rc, which has since gone into stable.

Commit 00442ad04a ("mempolicy: fix a memory corruption by refcount
imbalance in alloc_pages_vma()") changed get_vma_policy() to raise the
refcount on a shmem shared mempolicy; whereas shmem_alloc_page() went
on expecting alloc_page_vma() to drop the refcount it had acquired.
This deserves a rework: but for now fix the leak in shmem_alloc_page().

Hugh: shmem_swapin() did not need a fix, but surely it's clearer to use
the same refcounting there as in shmem_alloc_page(), delete its onstack
mempolicy, and the strange mpol_cond_copy() and __mpol_cond_copy() -
those were invented to let swapin_readahead() make an unknown number of
calls to alloc_pages_vma() with one mempolicy; but since 00442ad04a,
alloc_pages_vma() has kept refcount in balance, so now no problem.

Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-06 11:56:43 -08:00
Linus Torvalds
df2fc246c8 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module fixes from Rusty Russell:
 "Module signing build fixes for blackfin and metag"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modsign: add symbol prefix to certificate list
  linux/kernel.h: define SYMBOL_PREFIX
2012-12-04 09:32:12 -08:00
Linus Torvalds
d3594ea2b3 Merge branch 'block-dev'
Merge 'block-dev' branch.

I was going to just mark everything here for stable and leave it to the
3.8 merge window, but having decided on doing another -rc, I migth as
well merge it now.

This removes the bd_block_size_semaphore semaphore that was added in
this release to fix a race condition between block size changes and
block IO, and replaces it with atomicity guaratees in fs/buffer.c
instead, along with simplifying fs/block-dev.c.

This removes more lines than it adds, makes the code generally simpler,
and avoids the latency/rt issues that the block size semaphore
introduced for mount.

I'm not happy with the timing, but it wouldn't be much better doing this
during the merge window and then having some delayed back-port of it
into stable.

* block-dev:
  blkdev_max_block: make private to fs/buffer.c
  direct-io: don't read inode->i_blkbits multiple times
  blockdev: remove bd_block_size_semaphore again
  fs/buffer.c: make block-size be per-page and protected by the page lock
2012-12-03 10:53:25 -08:00
James Hogan
cbdbf2abb7 linux/kernel.h: define SYMBOL_PREFIX
Define SYMBOL_PREFIX to be the same as CONFIG_SYMBOL_PREFIX if set by
the architecture, or "" otherwise. This avoids the need for ugly #ifdefs
whenever symbols are referenced in asm blocks.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-03 13:05:54 +10:30
Linus Torvalds
455e987c0c Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "This is mostly about unbreaking architectures that took the UAPI
  changes in the v3.7 cycle, plus misc fixes."

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf kvm: Fix building perf kvm on non x86 arches
  perf kvm: Rename perf_kvm to perf_kvm_stat
  perf: Make perf build for x86 with UAPI disintegration applied
  perf powerpc: Use uapi/unistd.h to fix build error
  tools: Pass the target in descend
  tools: Honour the O= flag when tool build called from a higher Makefile
  tools: Define a Makefile function to do subdir processing
  x86: Export asm/{svm.h,vmx.h,perf_regs.h}
  perf tools: Fix strbuf_addf() when the buffer needs to grow
  perf header: Fix numa topology printing
  perf, powerpc: Fix hw breakpoints returning -ENOSPC
2012-12-01 13:07:48 -08:00
Linus Torvalds
50a53bbe12 Merge branch 'akpm' (Fixes from Andrew)
Merge misc fixes from Andrew Morton:
 "Seven fixes, some of them fingers-crossed :("

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (7 patches)
  drivers/rtc/rtc-tps65910.c: fix invalid pointer access on _remove()
  mm: soft offline: split thp at the beginning of soft_offline_page()
  mm: avoid waking kswapd for THP allocations when compaction is deferred or contended
  revert "Revert "mm: remove __GFP_NO_KSWAPD""
  mm: vmscan: fix endless loop in kswapd balancing
  mm/vmemmap: fix wrong use of virt_to_page
  mm: compaction: fix return value of capture_free_page()
2012-11-30 10:46:43 -08:00
Andrew Morton
a50915394f revert "Revert "mm: remove __GFP_NO_KSWAPD""
It apepars that this patch was innocent, and we hope that "mm: avoid
waking kswapd for THP allocations when compaction is deferred or
contended" will fix the final kswapd-spinning cause.

Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-30 08:51:17 -08:00
Linus Torvalds
bbec0270bd blkdev_max_block: make private to fs/buffer.c
We really don't want to look at the block size for the raw block device
accesses in fs/block-dev.c, because it may be changing from under us.
So get rid of the max_block logic entirely, since the caller should
already have done it anyway.

That leaves the only user of this function in fs/buffer.c, so move the
whole function there and make it static.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-29 17:48:12 -08:00
Linus Torvalds
1e8b33328a blockdev: remove bd_block_size_semaphore again
This reverts the block-device direct access code to the previous
unlocked code, now that fs/buffer.c no longer needs external locking.

With this, fs/block_dev.c is back to the original version, apart from a
whitespace cleanup that I didn't want to revert.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-29 10:52:19 -08:00
Frederic Weisbecker
d37f761dbd cputime: Consolidate cputime adjustment code
task_cputime_adjusted() and thread_group_cputime_adjusted()
essentially share the same code. They just don't use the same
source:

* The first function uses the cputime in the task struct and the
previous adjusted snapshot that ensures monotonicity.

* The second adds the cputime of all tasks in the group and the
previous adjusted snapshot of the whole group from the signal
structure.

Just consolidate the common code that does the adjustment. These
functions just need to fetch the values from the appropriate
source.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-28 17:08:10 +01:00
Frederic Weisbecker
e80d0a1ae8 cputime: Rename thread_group_times to thread_group_cputime_adjusted
We have thread_group_cputime() and thread_group_times(). The naming
doesn't provide enough information about the difference between
these two APIs.

To lower the confusion, rename thread_group_times() to
thread_group_cputime_adjusted(). This name better suggests that
it's a version of thread_group_cputime() that does some stabilization
on the raw cputime values. ie here: scale on top of CFS runtime
stats and bound lower value for monotonicity.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-28 17:07:57 +01:00
Mikulas Patocka
4b05a1c74d percpu-rwsem: use synchronize_sched_expedited
Use synchronize_sched_expedited() instead of synchronize_sched()
to improve mount speed.

This patch improves mount time from 0.500s to 0.013s for Jeff's
test-case.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-28 07:33:50 -08:00
Mel Gorman
82b212f400 Revert "mm: remove __GFP_NO_KSWAPD"
With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction
based on failures" reverted, Zdenek Kabelac reported the following

  Hmm,  so it's just took longer to hit the problem and observe
  kswapd0 spinning on my CPU again - it's not as endless like before -
  but still it easily eats minutes - it helps to	turn off  Firefox
  or TB  (memory hungry apps) so kswapd0 stops soon - and restart
  those apps again.  (And I still have like >1GB of cached memory)

  kswapd0         R  running task        0    30      2 0x00000000
  Call Trace:
    preempt_schedule+0x42/0x60
    _raw_spin_unlock+0x55/0x60
    put_super+0x31/0x40
    drop_super+0x22/0x30
    prune_super+0x149/0x1b0
    shrink_slab+0xba/0x510

The sysrq+m indicates the system has no swap so it'll never reclaim
anonymous pages as part of reclaim/compaction.  That is one part of the
problem but not the root cause as file-backed pages could also be
reclaimed.

The likely underlying problem is that kswapd is woken up or kept awake
for each THP allocation request in the page allocator slow path.

If compaction fails for the requesting process then compaction will be
deferred for a time and direct reclaim is avoided.  However, if there
are a storm of THP requests that are simply rejected, it will still be
the the case that kswapd is awake for a prolonged period of time as
pgdat->kswapd_max_order is updated each time.  This is noticed by the
main kswapd() loop and it will not call kswapd_try_to_sleep().  Instead
it will loopp, shrinking a small number of pages and calling
shrink_slab() on each iteration.

The temptation is to supply a patch that checks if kswapd was woken for
THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not
backed up by proper testing.  As 3.7 is very close to release and this
is not a bug we should release with, a safer path is to revert "mm:
remove __GFP_NO_KSWAPD" for now and revisit it with the view to ironing
out the balance_pgdat() logic in general.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-26 17:41:24 -08:00
Tushar Behera
c5782e9f5a include/linux/bug.h: fix sparse warning related to BUILD_BUG_ON_INVALID
Commit baf05aa927 ("bug: introduce BUILD_BUG_ON_INVALID() macro")
introduces this macro only when _CHECKER_ is not defined.  Define a
silent macro in the else condition to fix following sparse warning:

  mm/filemap.c:395:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
  mm/filemap.c:396:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
  mm/filemap.c:397:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
  include/linux/mm.h:419:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
  include/linux/mm.h:419:9: error: not a function <noident>

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-26 17:41:24 -08:00
Linus Torvalds
5e351cdc99 Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6
Pull device tree regression fix from Grant Likely:
 "Simple build regression fix for DT device drivers on Sparc.  An
  earlier change had masked out the of_iomap() helper on SPARC."

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  of/address: sparc: Declare of_iomap as an extern function for sparc again
2012-11-23 12:36:06 -10:00
Andreas Larsson
0e622d3919 of/address: sparc: Declare of_iomap as an extern function for sparc again
This bug-fix makes sure that of_iomap is defined extern for sparc so that the
sparc-specific implementation of_iomap is once again used when including
include/linux/of_address.h in a sparc context. OF_GPIO that is now available for
sparc relies on this.

The bug was inadvertently introduced in a850a75, "of/address: add empty static
inlines for !CONFIG_OF", that added a static dummy inline for of_iomap when
!CONFIG_OF_ADDRESS. However, CONFIG_OF_ADDRESS is never defined for sparc, but
there is a sparc-specific implementation /arch/sparc/kernel/of_device_common.c.

This fix takes the same approach as 0bce04b that solved the equivalent problem
for of_address_to_resource.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-11-23 22:01:15 +00:00
Linus Torvalds
33f1459340 Merge branch 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
 "Bugfixes for the i2c subsystem.

  Except for a few one-liners, there is mainly one revert because of an
  overlooked dependency.  Since there is no linux-next at the moment, I
  did some extra testing, and all was fine for me."

* 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux:
  i2c: mxs: Handle i2c DMA failure properly
  i2c: s3c2410: Fix code to free gpios
  i2c: omap: ensure writes to dev->buf_len are ordered
  Revert "ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints"
  i2c: at91: fix SMBus quick command
2012-11-23 11:59:26 -10:00
Linus Torvalds
26d29d06ea Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
 "This fixes recent regression where /dev/input/mice got assigned wrong
  device node which messed up setups with static /dev, and a regression
  in ads7846 GPIO debounce setup."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  ARM - OMAP: ads7846: fix pendown debounce setting
  Input: ads7846 - enable pendown GPIO debounce time setting
  Input: mousedev - move /dev/input/mice to the correct minor
  Input: MT - document new 'flags' argument of input_mt_init_slots()
2012-11-22 21:45:34 -10:00
Igor Grinberg
c4f4925439 Input: ads7846 - enable pendown GPIO debounce time setting
Some platforms need the pendown GPIO debounce time setting programmed.
Since the pendown GPIO is handled by the driver, the debounce time
should also be handled along with the pendown GPIO request.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2012-11-21 13:09:56 -08:00
David Howells
d2709c7ce4 perf: Make perf build for x86 with UAPI disintegration applied
Make perf build for x86 once the UAPI disintegration patches for that arch
have been applied by adding the appropriate -I flags - in the right order -
and then converting some #includes that use ../.. notation to find main kernel
headerfiles to use <asm/foo.h> and <linux/foo.h> instead.

Note that -Iarch/foo/include/uapi is present _before_ -Iarch/foo/include.
This makes sure we get the userspace version of the pt_regs struct.  Ideally,
we wouldn't have the latter -I flag at all, but unfortunately we want
asm/svm.h and asm/vmx.h in builtin-kvm.c and these aren't part of the UAPI -
at least not for x86.  I wonder if the bits outside of the __KERNEL__ guards
*should* be transferred there.

I note also that perf seems to do its dependency handling manually by listing
all the header files it might want to use in LIB_H in the Makefile.  Can this
be changed to use -MD?

Note that to do make this work, we need to export and UAPI disintegrate
linux/hw_breakpoint.h, which I think should've been exported previously so that
perf can access the bits.  We have to do this in the same patch to maintain
bisectability.

Signed-off-by: David Howells <dhowells@redhat.com>
2012-11-19 22:21:03 +00:00
Frederic Weisbecker
bcebdf8465 vtime: Explicitly account pending user time on process tick
All vtime implementations just flush the user time on process
tick. Consolidate that in generic code by calling a user time
accounting helper. This avoids an indirect call in ia64 and
prepare to also consolidate vtime context switch code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-11-19 16:41:21 +01:00
Frederic Weisbecker
fd25b4c2f2 vtime: Remove the underscore prefix invasion
Prepending irq-unsafe vtime APIs with underscores was actually
a bad idea as the result is a big mess in the API namespace that
is even waiting to be further extended. Also these helpers
are always called from irq safe callers except kvm. Just
provide a vtime_account_system_irqsafe() for this specific
case so that we can remove the underscore prefix on other
vtime functions.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-11-19 16:40:16 +01:00
Linus Torvalds
0cad3ff404 Merge branch 'akpm' (Fixes from Andrew)
Merge misc fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (12 patches)
  revert "mm: fix-up zone present pages"
  tmpfs: change final i_blocks BUG to WARNING
  tmpfs: fix shmem_getpage_gfp() VM_BUG_ON
  mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address
  mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures"
  rapidio: fix kernel-doc warnings
  swapfile: fix name leak in swapoff
  memcg: fix hotplugged memory zone oops
  mips, arc: fix build failure
  memcg: oom: fix totalpages calculation for memory.swappiness==0
  mm: fix build warning for uninitialized value
  mm: add anon_vma_lock to validate_mm()
2012-11-16 15:26:38 -08:00
Andrew Morton
5576646f3c revert "mm: fix-up zone present pages"
Revert commit 7f1290f2f2 ("mm: fix-up zone present pages")

That patch tried to fix a issue when calculating zone->present_pages,
but it caused a regression on 32bit systems with HIGHMEM.  With that
change, reset_zone_present_pages() resets all zone->present_pages to
zero, and fixup_zone_present_pages() is called to recalculate
zone->present_pages when the boot allocator frees core memory pages into
buddy allocator.  Because highmem pages are not freed by bootmem
allocator, all highmem zones' present_pages becomes zero.

Various options for improving the situation are being discussed but for
now, let's return to the 3.6 code.

Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-16 14:33:04 -08:00
Randy Dunlap
2ca3cb50ed rapidio: fix kernel-doc warnings
Fix rapidio kernel-doc warnings:

  Warning(drivers/rapidio/rio.c:415): No description found for parameter 'local'
  Warning(drivers/rapidio/rio.c:415): Excess function parameter 'lstart' description in 'rio_map_inb_region'
  Warning(include/linux/rio.h:290): No description found for parameter 'switches'
  Warning(include/linux/rio.h:290): No description found for parameter 'destid_table'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-16 14:33:04 -08:00
Hugh Dickins
bea8c150a7 memcg: fix hotplugged memory zone oops
When MEMCG is configured on (even when it's disabled by boot option),
when adding or removing a page to/from its lru list, the zone pointer
used for stats updates is nowadays taken from the struct lruvec.  (On
many configurations, calculating zone from page is slower.)

But we have no code to update all the lruvecs (per zone, per memcg) when
a memory node is hotadded.  Here's an extract from the oops which
results when running numactl to bind a program to a newly onlined node:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000f60
  IP:  __mod_zone_page_state+0x9/0x60
  Pid: 1219, comm: numactl Not tainted 3.6.0-rc5+ #180 Bochs Bochs
  Process numactl (pid: 1219, threadinfo ffff880039abc000, task ffff8800383c4ce0)
  Call Trace:
    __pagevec_lru_add_fn+0xdf/0x140
    pagevec_lru_move_fn+0xb1/0x100
    __pagevec_lru_add+0x1c/0x30
    lru_add_drain_cpu+0xa3/0x130
    lru_add_drain+0x2f/0x40
   ...

The natural solution might be to use a memcg callback whenever memory is
hotadded; but that solution has not been scoped out, and it happens that
we do have an easy location at which to update lruvec->zone.  The lruvec
pointer is discovered either by mem_cgroup_zone_lruvec() or by
mem_cgroup_page_lruvec(), and both of those do know the right zone.

So check and set lruvec->zone in those; and remove the inadequate
attempt to set lruvec->zone from lruvec_init(), which is called before
NODE_DATA(node) has been allocated in such cases.

Ah, there was one exceptionr.  For no particularly good reason,
mem_cgroup_force_empty_list() has its own code for deciding lruvec.
Change it to use the standard mem_cgroup_zone_lruvec() and
mem_cgroup_get_lru_size() too.  In fact it was already safe against such
an oops (the lru lists in danger could only be empty), but we're better
proofed against future changes this way.

I've marked this for stable (3.6) since we introduced the problem in 3.5
(now closed to stable); but I have no idea if this is the only fix
needed to get memory hotadd working with memcg in 3.6, and received no
answer when I enquired twice before.

Reported-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-16 14:33:04 -08:00
Linus Torvalds
f4bcd79c88 Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
 "We've been sitting on this longer than we meant to due to travel and
  other activities, but the number of patches is luckily not that high.

  Biggest changes are from a batch of OMAP bugfixes, but there are a few
  for the broader set of SoCs too (bcm2835, pxa, highbank, tegra, at91
  and i.MX).

  The OMAP patches contain some fixes for MUSB/PHY on omap4 which ends
  up being a bit on the large side but needed for legacy (non-DT)
  platforms.  Beyond that there are a handful of hwmod/pm changes.

  So, fairly noncontroversial stuff all in all, and as usual around this
  time the fixes are well targeted at specific problems."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: imx: ehci: fix host power mask bit
  ARM i.MX: fix error-valued pointer dereference in clk_register_gate2()
  ARM: at91/usbh: fix overcurrent gpio setup
  ARM: at91/AT91SAM9G45: fix crypto peripherals irq issue due to sparse irq support
  ARM: boot: Fix usage of kecho
  ARM: OMAP: ocp2scp: create omap device for ocp2scp
  ARM: OMAP4: add _dev_attr_ to ocp2scp for representing usb_phy
  drivers: bus: ocp2scp: add pdata support
  irqchip: irq-bcm2835: Add terminating entry for of_device_id table
  ARM: highbank: retry wfi on reset request
  ARM: OMAP4: PM: fix regulator name for VDD_MPU
  ARM: OMAP4: hwmod data: do not enable or reset the McPDM during kernel init
  ARM: OMAP2+: hwmod: add flag to prevent hwmod code from touching IP block during init
  ARM: dt: tegra: fix length of pad control and mux registers
  ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod
  ARM: OMAP2+: clockdomain: Fix OMAP4 ISS clk domain to support only SWSUP
  ARM: pxa/spitz_pm: Fix hang when resuming from STR
  ARM: pxa: hx4700: Fix backlight PWM device number
  ARM: OMAP2+: PM: add missing newline to VC warning message
2012-11-16 10:08:45 -08:00
Arnd Bergmann
57260e4088 Merge tag 'imx-fixes-rc' of git://git.pengutronix.de/git/imx/linux-2.6 into fixes
From Sascha Hauer <s.hauer@pengutronix.de>:

ARM i.MX fixes for 3.7-rc

* tag 'imx-fixes-rc' of git://git.pengutronix.de/git/imx/linux-2.6:
  ARM: imx: ehci: fix host power mask bit
  ARM i.MX: fix error-valued pointer dereference in clk_register_gate2()

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-11-16 16:42:59 +01:00
Igor Mazanov
93532c8a48 clk: remove inline usage from clk-provider.h
Users of GCC 4.7 have reported compiler errors due to having inline
applied to function declarations in clk-provider.h.  The definitions
exist in drivers/clk/clk.c.  An example error:

In file included from arch/arm/mach-omap2/clockdomain.c:25:0:
arch/arm/mach-omap2/clockdomain.c: In function ‘clkdm_clk_disable’:
include/linux/clk-provider.h:338:12: error: inlining failed in call to always_inline ‘__clk_get_enable_count’: function body not available
arch/arm/mach-omap2/clockdomain.c:1001:28: error: called from here
make[1]: *** [arch/arm/mach-omap2/clockdomain.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2

This patch removes the use of inline from include/linux/clk-provider.h
but keeps the function definitions in drivers/clk/clk.c as inlined since
they are one-liners.

Signed-off-by: Igor Mazanov <i.mazanov@gmail.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improved subject, added changelog]
2012-11-15 11:38:34 -08:00
Paul Walmsley
9aadd70aed Revert "ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints"
This reverts commit 3db11feffc
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-14 11:54:41 +01:00
Ingo Molnar
a7a0aaa17a Merge tag 'v3.7-rc5' into sched/core
Merge Linux 3.7-rc5, to pick up fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-11-14 08:49:49 +01:00
Linus Torvalds
b251f0f399 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Bug fixes galore, mostly in drivers as is often the case:

  1) USB gadget and cdc_eem drivers need adjustments to their frame size
     lengths in order to handle VLANs correctly.  From Ian Coolidge.

  2) TIPC and several network drivers erroneously call tasklet_disable
     before tasklet_kill, fix from Xiaotian Feng.

  3) r8169 driver needs to apply the WOL suspend quirk to more chipsets,
     fix from Cyril Brulebois.

  4) Fix multicast filters on RTL_GIGA_MAC_VER_35 r8169 chips, from
     Nathan Walp.

  5) FDB netlink dumps should use RTM_NEWNEIGH as the message type, not
     zero.  From John Fastabend.

  6) Fix smsc95xx tx checksum offload on big-endian, from Steve
     Glendinning.

  7) __inet_diag_dump() needs to repsect and report the error value
     returned from inet_diag_lock_handler() rather than ignore it.
     Otherwise if an inet diag handler is not available for a particular
     protocol, we essentially report success instead of giving an error
     indication.  Fix from Cyrill Gorcunov.

  8) When the QFQ packet scheduler sees TSO/GSO packets it does not
     handle things properly, and in fact ends up corrupting it's
     datastructures as well as mis-schedule packets.  Fix from Paolo
     Valente.

  9) Fix oopser in skb_loop_sk(), from Eric Leblond.

  10) CXGB4 passes partially uninitialized datastructures in to FW
      commands, fix from Vipul Pandya.

  11) When we send unsolicited ipv6 neighbour advertisements, we should
      send them to the link-local allnodes multicast address, as per
      RFC4861.  Fix from Hannes Frederic Sowa.

  12) There is some kind of bug in the usbnet's kevent deferral
      mechanism, but more immediately when it triggers an uncontrolled
      stream of kernel messages spam the log.  Rate limit the error log
      message triggered when this problem occurs, as sending thousands
      of error messages into the kernel log doesn't help matters at all,
      and in fact makes further diagnosis more difficult.

      From Steve Glendinning.

  13) Fix gianfar restore from hibernation, from Wang Dongsheng.

  14) The netlink message attribute sizes are wrong in the ipv6 GRE
      driver, it was using the size of ipv4 addresses instead of ipv6
      ones :-) Fix from Nicolas Dichtel."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  gre6: fix rtnl dump messages
  gianfar: ethernet vanishes after restoring from hibernation
  usbnet: ratelimit kevent may have been dropped warnings
  ipv6: send unsolicited neighbour advertisements to all-nodes
  net: usb: cdc_eem: Fix rx skb allocation for 802.1Q VLANs
  usb: gadget: g_ether: fix frame size check for 802.1Q
  cxgb4: Fix initialization of SGE_CONTROL register
  isdn: Make CONFIG_ISDN depend on CONFIG_NETDEVICES
  cxgb4: Initialize data structures before using.
  af-packet: fix oops when socket is not present
  pkt_sched: enable QFQ to support TSO/GSO
  net: inet_diag -- Return error code if protocol handler is missed
  net: bnx2x: Fix typo in bnx2x driver
  smsc95xx: fix tx checksum offload for big endian
  rtnetlink: Use nlmsg type RTM_NEWNEIGH from dflt fdb dump
  ptp: update adjfreq callback description
  r8169: allow multicast packets on sub-8168f chipset.
  r8169: Fix WoL on RTL8168d/8111d.
  drivers/net: use tasklet_kill in device remove/close process
  tipc: do not use tasklet_disable before tasklet_kill
2012-11-10 22:03:49 +01:00
Linus Torvalds
2b1768f39a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc fixes from David Miller:
 "Several build/bug fixes for sparc, including:

  1) Configuring a mix of static vs.  modular sparc64 crypto modules
     didn't work, remove an ill-conceived attempt to only have to build
     the device match table for these drivers once to fix the problem.

     Reported by Meelis Roos.

  2) Make the montgomery multiple/square and mpmul instructions actually
     usable in 32-bit tasks.  Essentially this involves providing 32-bit
     userspace with a way to use a 64-bit stack when it needs to.

  3) Our sparc64 atomic backoffs don't yield cpu strands properly on
     Niagara chips.  Use pause instruction when available to achieve
     this, otherwise use a benign instruction we know blocks the strand
     for some time.

  4) Wire up kcmp

  5) Fix the build of various drivers by removing the unnecessary
     blocking of OF_GPIO when SPARC.

  6) Fix unintended regression wherein of_address_to_resource stopped
     being provided.  Fix from Andreas Larsson.

  7) Fix NULL dereference in leon_handle_ext_irq(), also from Andreas
     Larsson."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix build with mix of modular vs. non-modular crypto drivers.
  sparc: Support atomic64_dec_if_positive properly.
  of/address: sparc: Declare of_address_to_resource() as an extern function for sparc again
  sparc32, leon: Check for existent irq_map entry in leon_handle_ext_irq
  sparc: Add sparc support for platform_get_irq()
  sparc: Allow OF_GPIO on sparc.
  qlogicpti: Fix build warning.
  sparc: Wire up sys_kcmp.
  sparc64: Improvde documentation and readability of atomic backoff code.
  sparc64: Use pause instruction when available.
  sparc64: Fix cpu strand yielding.
  sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads.
2012-11-10 21:58:34 +01:00
Andreas Larsson
0bce04be44 of/address: sparc: Declare of_address_to_resource() as an extern function for sparc again
This bug-fix makes sure that of_address_to_resource is defined extern for sparc
so that the sparc-specific implementation of of_address_to_resource() is once
again used when including include/linux/of_address.h in a sparc context. A
number of drivers in mainline relies on this function working for sparc.

The bug was introduced in a850a75544, "of/address:
add empty static inlines for !CONFIG_OF". Contrary to that commit title, the
static inlines are added for !CONFIG_OF_ADDRESS, and CONFIG_OF_ADDRESS is never
defined for sparc. This is good behavior for the other functions in
include/linux/of_address.h, as the extern functions defined in
drivers/of/address.c only gets linked when OF_ADDRESS is configured. However,
for of_address_to_resource there exists a sparc-specific implementation in
arch/sparc/arch/sparc/kernel/of_device_common.c

Solution suggested by: Sam Ravnborg <sam@ravnborg.org>

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-09 16:30:50 -08:00
Linus Torvalds
a4275153cc Merge tag 'mmc-fixes-for-3.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
Pull MMC fixes from Chris Ball:
 - sdhci: fix a NULL dereference at resume-time, seen on OLPC XO-4
 - sdhci: fix against 3.7-rc1 for UHS modes without a vqmmc regulator
 - sdhci-of-esdhc: disable CMD23 on boards where it's broken
 - sdhci-s3c: fix against 3.7-rc1 for card detection with runtime PM
 - dw_mmc, omap_hsmmc: fix potential NULL derefs, compiler warnings

* tag 'mmc-fixes-for-3.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc:
  mmc: sdhci-s3c: fix the card detection in runtime-pm
  mmc: sdhci-s3c: use clk_prepare_enable and clk_disable_unprepare
  mmc: dw_mmc: constify dw_mci_idmac_ops in exynos back-end
  mmc: dw_mmc: fix modular build for exynos back-end
  mmc: sdhci: fix NULL dereference in sdhci_request() tuning
  mmc: sdhci: fix IS_ERR() checking of regulator_get()
  mmc: fix sdhci-dove probe/removal
  mmc: sh_mmcif: fix use after free
  mmc: sdhci-pci: fix 'Invalid iomem size' error message condition
  mmc: mxcmmc: Fix MODULE_ALIAS
  mmc: omap_hsmmc: fix NULL pointer dereference for dt boot
  mmc: omap_hsmmc: fix host reference after mmc_free_host
  mmc: dw_mmc: fix multiple drv_data NULL dereferences
  mmc: dw_mmc: enable controller interrupt before calling mmc_start_host
  mmc: sdhci-of-esdhc: disable CMD23 for some Freescale SoCs
  mmc: dw_mmc: remove _dev_info compile warning
  mmc: dw_mmc: convert the variable type of irq
2012-11-09 21:32:33 +01:00
Arnd Bergmann
8e2b36ea6e mmc: dw_mmc: constify dw_mci_idmac_ops in exynos back-end
The of_device_id match data is now marked as const and
must not be modified. This changes the dw_mmc to mark
all pointers passing the dw_mci_drv_data or dw_mci_dma_ops
structures as const, and also marks the static definitions
as const.

drivers/mmc/host/dw_mmc-exynos.c: In function 'dw_mci_exynos_probe':
drivers/mmc/host/dw_mmc-exynos.c:234:11: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Abraham <thomas.abraham@linaro.org>
Cc: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-11-07 15:02:55 -05:00
Jerry Huang
63ef5d8c28 mmc: sdhci-of-esdhc: disable CMD23 for some Freescale SoCs
CMD23 causes lots of errors in kernel on some freescale SoCs
(P1020, P1021, P1022, P1024, P1025 and P4080) when MMC card used,
which is because these controllers does not support CMD23,
even on the SoCs which declares CMD23 is supported.
Therefore, we'll not use CMD23.

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-11-07 14:55:29 -05:00
Seungwon Jeon
d676188e44 mmc: dw_mmc: convert the variable type of irq
Even though platform_get_irq returns error, 'host->irq'
always has an unsigned value. Less-than-zero comparison
of an unsigned value is never true. Type of 'unsigned int'
will be changed for 'int'.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-11-07 14:50:16 -05:00
Kishon Vijay Abraham I
0133370f93 drivers: bus: ocp2scp: add pdata support
ocp2scp was not having pdata support which makes *musb* fail for non-dt
boot in OMAP platform. The pdata will have information about the devices
that is connected to ocp2scp. ocp2scp driver will now make use of this
information to create the devices that is attached to ocp2scp.

This is needed to fix MUSB regression caused by commit c9e4412a
(arm: omap: phy: remove unused functions from omap-phy-internal.c)

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
[tony@atomide.com: updated comments for regression info]
Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-11-07 09:35:53 -08:00
Jacob Keller
87f4d7c1d3 ptp: update adjfreq callback description
This patch updates the adjfreq callback description to include a note that the
delta in ppb is always relative to the base frequency, and not to the current
frequency of the hardware clock.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
CC: stable@vger.kernel.org [v3.5+]
CC: Richard Cochran <richard.cochran@gmail.com>
CC: John Stultz <john.stultz@linaro.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-03 15:27:07 -04:00
Sasha Levin
d9b482c8ba hashtable: introduce a small and naive hashtable
This hashtable implementation is using hlist buckets to provide a simple
hashtable to prevent it from getting reimplemented all over the kernel.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
[ Merging this now, so that subsystems can start applying Sasha's
  patches that use this   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-02 12:44:51 -07:00
Linus Torvalds
8c23f406c6 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fix from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: fix vcpu->mmio_fragments overflow
2012-11-01 08:27:02 -07:00
Xiao Guangrong
87da7e66a4 KVM: x86: fix vcpu->mmio_fragments overflow
After commit b3356bf0db (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together

Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow

The bug can be exposed by isapc (-M isapc):

[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874]  [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677]  [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604]  [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]

Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-31 20:36:30 -02:00
Linus Torvalds
2df4f26167 Merge tag 'md-3.7-fixes' of git://neil.brown.name/md
Pull md fixes from NeilBrown:
 "Some fixes for md in 3.7
   - one recently introduced crash for dm-raid10 with discard
   - one bug in new functionality that has been around for a few
     releases.
   - minor bug in md's 'faulty' personality

  and UAPI disintegration for md."

* tag 'md-3.7-fixes' of git://neil.brown.name/md:
  MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c
  md/raid1: Fix assembling of arrays containing Replacements.
  md faulty: use disk_stack_limits()
  UAPI: (Scripted) Disintegrate include/linux/raid
2012-10-30 19:48:48 -07:00
Frederic Weisbecker
3e1df4f506 cputime: Separate irqtime accounting from generic vtime
vtime_account() doesn't have the same role in
CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_IRQ_TIME_ACCOUNTING.

In the first case it handles time accounting in any context. In
the second case it only handles irq time accounting.

So when vtime_account() is called from outside vtime_account_irq_*()
this call is pointless to CONFIG_IRQ_TIME_ACCOUNTING.

To fix the confusion, change vtime_account() to irqtime_account_irq()
in CONFIG_IRQ_TIME_ACCOUNTING. This way we ensure future account_vtime()
calls won't waste useless cycles in the irqtime APIs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-10-29 21:31:32 +01:00
Frederic Weisbecker
fa5058f3b6 cputime: Specialize irq vtime hooks
With CONFIG_VIRT_CPU_ACCOUNTING, when vtime_account()
is called in irq entry/exit, we perform a check on the
context: if we are interrupting the idle task we
account the pending cputime to idle, otherwise account
to system time or its sub-areas: tsk->stime, hardirq time,
softirq time, ...

However this check for idle only concerns the hardirq entry
and softirq entry:

* Hardirq may directly interrupt the idle task, in which case
we need to flush the pending CPU time to idle.

* The idle task may be directly interrupted by a softirq if
it calls local_bh_enable(). There is probably no such call
in any idle task but we need to cover every case. Ksoftirqd
is not concerned because the idle time is flushed on context
switch and softirq in the end of hardirq have the idle time
already flushed from the hardirq entry.

In the other cases we always account to system/irq time:

* On hardirq exit we account the time to hardirq time.
* On softirq exit we account the time to softirq time.

To optimize this and avoid the indirect call to vtime_account()
and the checks it performs, specialize the vtime irq APIs and
only perform the check on irq entry. Irq exit can directly call
vtime_account_system().

CONFIG_IRQ_TIME_ACCOUNTING behaviour doesn't change and directly
maps to its own vtime_account() implementation. One may want
to take benefits from the new APIs to optimize irq time accounting
as well in the future.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-10-29 21:31:32 +01:00
Frederic Weisbecker
b080935c86 kvm: Directly account vtime to system on guest switch
Switching to or from guest context is done on ioctl context.
So by the time we call kvm_guest_enter() or kvm_guest_exit()
we know we are not running the idle task.

As a result, we can directly account the cputime using
vtime_account_system().

There are two good reasons to do this:

* We avoid some useless checks on guest switch. It optimizes
a bit this fast path.

* In the case of CONFIG_IRQ_TIME_ACCOUNTING, calling vtime_account()
checks for irq time to account. This is pointless since we know
we are not in an irq on guest switch. This is wasting cpu cycles
for no good reason. vtime_account_system() OTOH is a no-op in
this config option.

* We can remove the irq disable/enable around kvm guest switch in s390.

A further optimization may consist in introducing a vtime_account_guest()
that directly calls account_guest_time().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Xiantao Zhang <xiantao.zhang@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-10-29 21:31:31 +01:00