Commit graph

276885 commits

Author SHA1 Message Date
Christoph Hellwig
9f9c19ec1a xfs: fix the logspace waiting algorithm
Apply the scheme used in log_regrant_write_log_space to wake up any other
threads waiting for log space before the newly added one to
log_regrant_write_log_space as well, and factor the code into readable
helpers.  For each of the queues we have add two helpers:

 - one to try to wake up all waiting threads.  This helper will also be
   usable by xfs_log_move_tail once we remove the current opportunistic
   wakeups in it.
 - one to sleep on t_wait until enough log space is available, loosely
   modelled after Linux waitqueues.
 
And use them to reimplement the guts of log_regrant_write_log_space and
log_regrant_write_log_space.  These two function now use one and the same
algorithm for waiting on log space instead of subtly different ones before,
with an option to completely unify them in the near future.

Also move the filesystem shutdown handling to the common caller given
that we had to touch it anyway.

Based on hard debugging and an earlier patch from
Chandra Seetharaman <sekharan@us.ibm.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
Tested-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2011-12-06 14:19:47 -06:00
Felix Fietkau
162d12de65 ath9k: fix check for antenna diversity support
fixes a regression on single-stream chips introduced in
commit 43c3528430
"ath9k: implement .get_antenna and .set_antenna"

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Reported-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-12-06 15:06:34 -05:00
Linus Torvalds
b835c0f47f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Silence seq_scale() unused warning
  ipv4:correct description for tcp_max_syn_backlog
  pasemi_mac: Fix building as module
  netback: Fix alert message.
  r8169: fix Rx index race between FIFO overflow recovery and NAPI handler.
  r8169: Rx FIFO overflow fixes.
  ipv4: Fix peer validation on cached lookup.
  ipv4: make sure RTO_ONLINK is saved in routing cache
  iwlwifi: change the default behavior of watchdog timer
  iwlwifi: do not re-configure HT40 after associated
  iwlagn: fix HW crypto for TX-only keys
  Revert "mac80211: clear sta.drv_priv on reconfiguration"
  mac80211: fill rate filter for internal scan requests
  cfg80211: amend regulatory NULL dereference fix
  cfg80211: fix race on init and driver registration
2011-12-06 12:03:54 -08:00
John W. Linville
facda29d75 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/padovan/bluetooth 2011-12-06 14:59:32 -05:00
Linus Torvalds
091c0f86ba Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ftrace: Fix hash record accounting bug
  perf: Fix parsing of __print_flags() in TP_printk()
  jump_label: jump_label_inc may return before the code is patched
  ftrace: Remove force undef config value left for testing
  tracing: Restore system filter behavior
  tracing: fix event_subsystem ref counting
2011-12-06 11:54:33 -08:00
Gleb Natapov
b3d9468a8b perf, x86: Expose perf capability to other modules
KVM needs to know perf capability to decide which PMU it can expose to a
guest.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1320929850-10480-8-git-send-email-gleb@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:41:08 +01:00
Peter Zijlstra
c1d6f42f1a perf, x86: Implement arch event mask as quirk
Implement the disabling of arch events as a quirk so that we can print
a message along with it. This creates some visibility into the problem
space and could allow us to work on adding more work-around like the
AAJ80 one.

Requested-by: Ingo Molnar <mingo@elte.hu>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-wcja2z48wklzu1b0nkz0a5y7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:41:06 +01:00
Gleb Natapov
ffb871bc91 x86, perf: Disable non available architectural events
Intel CPUs report non-available architectural events in cpuid leaf
0AH.EBX. Use it to disable events that are not available according
to CPU.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1320929850-10480-7-git-send-email-gleb@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:41:05 +01:00
Peter Zijlstra
ac99b862fb jump_label: Provide jump_label_key initializers
Provide two initializers for jump_label_key that initialize it enabled
or disabled. Also modify all jump_label code to allow for jump_labels to be
initialized enabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Link: http://lkml.kernel.org/n/tip-p40e3yj21b68y03z1yv825e7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:41:03 +01:00
Peter Zijlstra
9cdbe1cbac jump_label, x86: Fix section mismatch
WARNING: arch/x86/kernel/built-in.o(.text+0x4c71): Section mismatch in
reference from the function arch_jump_label_transform_static() to the
function .init.text:text_poke_early()
The function arch_jump_label_transform_static() references
the function __init text_poke_early().
This is often because arch_jump_label_transform_static lacks a __init
annotation or the annotation of text_poke_early is wrong.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Link: http://lkml.kernel.org/n/tip-9lefe89mrvurrwpqw5h8xm8z@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 20:41:02 +01:00
Geert Uytterhoeven
5bf1e97dc3 m68k: Wire up process_vm_{read,write}v
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2011-12-06 20:37:58 +01:00
Antonio Quartulli
797399b415 batman-adv: delete global entry in case of roaming
When receiving a DEL change for a client due to a roaming event (change is
marked with TT_CLIENT_ROAM), each node  has to check if the client roamed
to itself or somewhere else.

In the latter case the global entry is kept to avoid having no route at all
otherwise we can safely delete the global entry

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2011-12-07 03:12:59 +08:00
Antonio Quartulli
03fc307045 batman-adv: in case of roaming mark the client with TT_CLIENT_ROAM
In case of a client roaming from node A to node B, the latter have to mark the
corresponding global entry with TT_CLIENT_ROAM (instead of TT_CLIENT_PENDING).

Marking a global entry with TT_CLIENT_PENDING will end up in keeping such entry
forever (because this flag is only meant to be used with local entries and it is
never checked on global ones).

In the worst case (all the clients roaming to the same node A) the local and the
global table will contain exactly the same clients. Batman-adv will continue to
work, but the memory usage is duplicated.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2011-12-07 03:12:55 +08:00
Stephen Boyd
681090902e net: Silence seq_scale() unused warning
On a CONFIG_NET=y build

net/core/secure_seq.c:22: warning: 'seq_scale' defined but not
used

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 13:59:16 -05:00
Ingo Molnar
cc991b83b3 Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core 2011-12-06 19:09:15 +01:00
Peter Pan(潘卫平)
99b53bdd81 ipv4:correct description for tcp_max_syn_backlog
Since commit c5ed63d66f24(tcp: fix three tcp sysctls tuning),
sysctl_max_syn_backlog is determined by tcp_hashinfo->ehash_mask,
and the minimal value is 128, and it will increase in proportion to the
memory of machine.
The original description for tcp_max_syn_backlog and sysctl_max_syn_backlog
are out of date.

Changelog:
V2: update description for sysctl_max_syn_backlog

Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Reviewed-by: Shan Wei <shanwei88@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06 13:02:28 -05:00
Yong Zhang
a33caeb118 lockdep, kmemcheck: Annotate ->lock in lockdep_init_map()
Since commit f59de89 ("lockdep: Clear whole lockdep_map on initialization"),
lockdep_init_map() will clear all the struct. But it will break
lock_set_class()/lock_set_subclass(). A typical race condition
is like below:

     CPU A                                   CPU B
lock_set_subclass(lockA);
 lock_set_class(lockA);
   lockdep_init_map(lockA);
     /* lockA->name is cleared */
     memset(lockA);
                                     __lock_acquire(lockA);
                                       /* lockA->class_cache[] is cleared */
                                       register_lock_class(lockA);
                                         look_up_lock_class(lockA);
                                           WARN_ON_ONCE(class->name !=
                                                     lock->name);

     lock->name = name;

So restore to what we have done before commit f59de89 but annotate
->lock with kmemcheck_mark_initialized() to suppress the kmemcheck
warning reported in commit f59de89.

Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Borislav Petkov <bp@alien8.de>
Suggested-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhy
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 18:18:13 +01:00
Christoph Hellwig
c29f7d457a xfs: fix nfs export of 64-bit inodes numbers on 32-bit kernels
The i_ino field in the VFS inode is of type unsigned long and thus can't
hold the full 64-bit inode number on 32-bit kernels.  We have the full
inode number in the XFS inode, so use that one for nfs exports.  Note
that I've also switched the 32-bit file handles types to it, just to make
the code more consistent and copy & paste errors less likely to happen.

Reported-by: Guoquan Yang <ygq51@hotmail.com>
Reported-by: Hank Peng <pengxihan@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2011-12-06 10:46:23 -06:00
Arnd Bergmann
24e71ef6d9 Merge branch 'fixes' of git://gitorious.org/linux-davinci/linux-davinci into fixes 2011-12-06 14:20:13 +00:00
Arnd Bergmann
af72617279 Merge branch 'mxs/fixes' of git://git.linaro.org/people/shawnguo/linux-2.6 into fixes 2011-12-06 14:18:36 +00:00
Arnd Bergmann
58a394b3fa Merge branch 'fixes' of git://gitorious.org/sirfprima2-kernel/sirfprima2-kernel into fixes 2011-12-06 14:17:22 +00:00
Sedat Dilek
89e0b9a3fd iommu/amd: Fix typo in kernel-parameters.txt
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-12-06 15:16:02 +01:00
Arnd Bergmann
fec607aab5 Merge branch 'imx/fix-irqdomain' of git://git.linaro.org/people/shawnguo/linux-2.6 into fixes 2011-12-06 14:15:02 +00:00
Arnd Bergmann
e6b6edf267 Merge branch 'at91-fixes' of git://github.com/at91linux/linux-at91 into fixes 2011-12-06 14:14:06 +00:00
Alan Cox
4e2b1c4f56 x86/intel_mid: Kconfig select fix
If we select a symbol it should have a type declared first
otherwise in some situations the config tools get upset. They
are currently perhaps a bit too resilient which is why this
wasn't noticed initially.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20111206132811.4041.32549.stgit@bob.linux.org.uk
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 14:40:50 +01:00
Will Deacon
6bd054096d ARM: 7185/1: perf: don't assign platform_device on unsupported CPUs
In the unlikely case that a platform registers a PMU platform_device
when running on a CPU that is unsupported by perf, we will encounter a
NULL dereference when trying to assign the platform_device to the
cpu_pmu structure.

This patch checks that the CPU is supported by perf before assigning
the platform_device.

Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-06 12:48:01 +00:00
Takashi Iwai
6c39d6aca1 Merge branch 'fix/asoc' into for-linus 2011-12-06 13:22:28 +01:00
Takashi Iwai
a020428364 ALSA: hda - Fix remaining VREF mute-LED NID check in post-3.1 changes
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-12-06 13:21:43 +01:00
Takashi Iwai
b5212878ab Merge branch 'fix/hda-idt-fix' into fix/hda 2011-12-06 13:19:25 +01:00
Takashi Iwai
f1a73746c6 ALSA: hda - Fix GPIO LED setup for IDT 92HD75 codecs
Some HP laptops with IDT 92HD75 codecs may use a GPIO > 4 for the mute
LED, but currently the driver doesn't check this properly, and confuses
the mute LED behavior.  This ended up with the silent output  on some
HP laptops due to  having another GPIO used as external amp control.

This patch fixes the problem by checking the max GPIO count and
comparing with the given value from DMI entry instead of magic fixed
value 4 and 8, and adding a new field to indicate the VREF mute-LED
behavior.

Reported-and-tested-by: Vitaliy Kulikov <Vitaliy.Kulikov@idt.com>
Cc: <stable@kernel.org> [v3.1]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-12-06 13:18:46 +01:00
Andrew Vagin
6340cfed48 perf header: Use event_name() to get an event name
perf_evsel.name may be not initialized

Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arun Sharma <asharma@fb.com>
Cc: devel@openvz.org
Link: http://lkml.kernel.org/r/1322471015-107825-2-git-send-email-avagin@openvz.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-12-06 09:22:48 -02:00
Uwe Kleine-König
de66a97901 ARM: 7187/1: fix unwinding for XIP kernels
The linker places the unwind tables in readonly sections. So when using
an XIP kernel these are located in ROM and cannot be modified.
For that reason the current approach to convert the relative offsets in
the unwind index to absolute addresses early in the boot process doesn't
work with XIP.

The offsets in the unwind index section are signed 31 bit numbers and
the structs are sorted by this offset. So it first has offsets between
0x40000000 and 0x7fffffff (i.e. the negative offsets) and then offsets
between 0x00000000 and 0x3fffffff. When seperating these two blocks the
numbers are sorted even when interpreting the offsets as unsigned longs.

So determine the first non-negative entry once and track that using the
new origin pointer. The actual bisection can then use a plain unsigned
long comparison. The only thing that makes the new bisection more
complicated is that the offsets are relative to their position in the
index section, so the key to search needs to be adapted accordingly in
each step.

Moreover several consts are added to catch future writes and rename the
member "addr" of struct unwind_idx to "addr_offset" to better match the
new semantic. (This has the additional benefit of breaking eventual
users at compile time to make them aware of the change.)

In my tests the new algorithm was a tad faster than the original and has
the additional upside of not needing the initial conversion and so saves
some boot time and it's possible to unwind even earlier.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-06 11:16:13 +00:00
Nicolas Pitre
974c07249b ARM: 7186/1: fix Kconfig issue with PHYS_OFFSET and !MMU
Commit 1b9f95f8ad (ARM: prepare for removal of a bunch of <mach/memory.h>
files) introduced CONFIG_PHYS_OFFSET but the Kconfig hex prompt did not
provide a default value.

This has the undesired side effect of breaking a reportedly used
trick for updating defconfigs on the fly for routine buildtesting
across all arch and all platforms, i.e.

	cp /path/to/somedefconfig .config ; yes "" | make oldconfig

because the config system will endlessly loop until a valid address is
provided.

However we can't just pick a random default value since it is likely to
be wrong for the majority of the boards as the right answer for this
option is quite varied.  So the fact that the config system insists on
having a proper value be entered is actually a good thing.

It turns out that only at91x40_defconfig has this problem because it has
CONFIG_MMU=n. However, in the !MMU case, there is already a CONFIG_DRAM_BASE
value that can be used here.  So let's use that as a default in that case
and suppress the redundant CONFIG_PHYS_OFFSET prompt.

Eventually the DRAM_BASE config option could simply be replaced by
PHYS_OFFSET directly, but that's a larger change better suited for later.

Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-06 11:16:13 +00:00
Axel Lin
f8f626f537 ASoC: Fix build dependency for SND_SOC_JZ4740_CODEC
Currently SND_SOC_JZ4740_CODEC depends on SOC_JZ4740 but SOC_JZ4740 is not
defined in any Kconfig. Thus the codec driver will not be built when select
"Build all ASoC CODEC drivers".
(Unless it is selected by SND_JZ4740_SOC_QI_LB60).
Remove the dependency with SOC_JZ4740, then this code driver can be built when
select "Build all ASoC CODEC drivers".

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-12-06 11:01:20 +00:00
Axel Lin
68bfcafaae ASoC: Include linux/io.h for jz4740 codec
Include linux/io.h to fix below build errors:

  CC      sound/soc/codecs/jz4740.o
sound/soc/codecs/jz4740.c: In function 'jz4740_codec_read':
sound/soc/codecs/jz4740.c:82: error: implicit declaration of function 'readl'
sound/soc/codecs/jz4740.c: In function 'jz4740_codec_write':
sound/soc/codecs/jz4740.c:92: error: implicit declaration of function 'writel'
sound/soc/codecs/jz4740.c: In function 'jz4740_codec_probe':
sound/soc/codecs/jz4740.c:373: error: implicit declaration of function 'ioremap'
sound/soc/codecs/jz4740.c:373: warning: assignment makes pointer from integer without a cast
sound/soc/codecs/jz4740.c:393: error: implicit declaration of function 'iounmap'
make[3]: *** [sound/soc/codecs/jz4740.o] Error 1
make[2]: *** [sound/soc/codecs] Error 2
make[1]: *** [sound/soc] Error 2
make: *** [sound] Error 2

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-12-06 11:01:10 +00:00
Thomas Gleixner
c9c024b3f3 alarmtimers: Fix time comparison
The expiry function compares the timer against current time and does
not expire the timer when the expiry time is >= now. That's wrong. If
the timer is set for now, then it must expire.

Make the condition expiry > now for breaking out the loop.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: stable@kernel.org
2011-12-06 11:38:32 +01:00
Thomas Gleixner
d68fb11c3d ptp: Fix clock_getres() implementation
The clock_getres() function must return the resolution in the timespec
argument and return 0 for success.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: stable@kernel.org
Cc: Richard Cochran <richard.cochran@omicron.at>
2011-12-06 11:38:32 +01:00
Alan Cox
dd13752537 x86/intel_mid: Fix the Kconfig for MID selection
We currently fail to build on CONFIG_X86_INTEL_MID=y and
CONFIG_X86_MRST unset.

We could build all the bits to make generic MID work if you
picked MID platform alone but that's really silly. Instead use
select and two variables.

This looks a bit daft right now but once we add a Medfield
selection it'll start to look a good deal more sensible.

Reported-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20111205231433.28811.51297.stgit@bob.linux.org.uk
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 11:28:36 +01:00
Joerg Roedel
96f176a310 iommu/msm: Fix compile error in mach-msm/devices-iommu.c
Fix compile error due to missing <linux/module.h> include.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-12-06 11:17:34 +01:00
Mark Brown
cefcc03ffc ASoC: Provide a more complete DMA driver stub
Allow userspace applications to do more parameter setting by providing a
more complete stub DMA driver specifying a wildcard set of formats and
channels and essentially random values for the DMA parameters. This is
required for useful runtime operation of the dummy DMA driver until we
are able to figure out how to power up links and do hw_params() from DAPM.

Sending to stable as without this the dummy driver is not terribly
useful.

Reported-by: Kyung-Kwee Ryu <Kyung-Kwee.Ryu@wolfsonmicro.com>
Tested-by: Kyung-Kwee Ryu <Kyung-Kwee.Ryu@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
2011-12-06 10:05:07 +00:00
Gleb Natapov
b202952075 perf, core: Rate limit perf_sched_events jump_label patching
jump_lable patching is very expensive operation that involves pausing all
cpus. The patching of perf_sched_events jump_label is easily controllable
from userspace by unprivileged user.

When te user runs a loop like this:

  "while true; do perf stat -e cycles true; done"

... the performance of my test application that just increments a counter
for one second drops by 4%.

This is on a 16 cpu box with my test application using only one of
them. An impact on a real server doing real work will be worse.

Performance of KVM PMU drops nearly 50% due to jump_lable for "perf
record" since KVM PMU implementation creates and destroys perf event
frequently.

This patch introduces a way to rate limit jump_label patching and uses
it to fix the above problem.

I believe that as jump_label use will spread the problem will become more
common and thus solving it in a generic code is appropriate. Also fixing
it in the perf code would result in moving jump_label accounting logic to
perf code with all the ifdefs in case of JUMP_LABEL=n kernel. With this
patch all details are nicely hidden inside jump_label code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111127155909.GO2557@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:34:02 +01:00
Peter Zijlstra
b79387ef18 perf: Fix enable_on_exec for sibling events
Deng-Cheng Zhu reported that sibling events that were created disabled
with enable_on_exec would never get enabled. Iterate all events
instead of the group lists.

Reported-by: Deng-Cheng Zhu <dczhu@mips.com>
Tested-by: Deng-Cheng Zhu <dczhu@mips.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322048382.14799.41.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:34:01 +01:00
Peter Zijlstra
1d9b482e78 perf: Remove superfluous arguments
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-yv4o74vh90suyghccgykbnry@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:33:59 +01:00
Peter Zijlstra
4defea8559 perf, x86: Prefer fixed-purpose counters when scheduling
This avoids a scheduling failure for cases like:

  cycles, cycles, instructions, instructions (on Core2)

Which would end up being programmed like:

  PMC0, PMC1, FP-instructions, fail

Because all events will have the same weight.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-8tnwb92asqj7xajqqoty4gel@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:33:58 +01:00
Robert Richter
bc1738f6ee perf, x86: Fix event scheduler for constraints with overlapping counters
The current x86 event scheduler fails to resolve scheduling problems
of certain combinations of events and constraints. This happens if the
counter mask of such an event is not a subset of any other counter
mask of a constraint with an equal or higher weight, e.g. constraints
of the AMD family 15h pmu:

                        counter mask    weight

 amd_f15_PMC30          0x09            2  <--- overlapping counters
 amd_f15_PMC20          0x07            3
 amd_f15_PMC53          0x38            3

The scheduler does not find then an existing solution. Here is an
example:

 event code     counter         failure         possible solution

 0x02E          PMC[3,0]        0               3
 0x043          PMC[2:0]        1               0
 0x045          PMC[2:0]        2               1
 0x046          PMC[2:0]        FAIL            2

The event scheduler may not select the correct counter in the first
cycle because it needs to know which subsequent events will be
scheduled. It may fail to schedule the events then.

To solve this, we now save the scheduler state of events with
overlapping counter counstraints.  If we fail to schedule the events
we rollback to those states and try to use another free counter.

Constraints with overlapping counters are marked with a new introduced
overlap flag. We set the overlap flag for such constraints to give the
scheduler a hint which events to select for counter rescheduling. The
EVENT_CONSTRAINT_OVERLAP() macro can be used for this.

Care must be taken as the rescheduling algorithm is O(n!) which will
increase scheduling cycles for an over-commited system dramatically.
The number of such EVENT_CONSTRAINT_OVERLAP() macros and its counter
masks must be kept at a minimum. Thus, the current stack is limited to
2 states to limit the number of loops the algorithm takes in the worst
case.

On systems with no overlapping-counter constraints, this
implementation does not increase the loop count compared to the
previous algorithm.

V2:
* Renamed redo -> overlap.
* Reimplementation using perf scheduling helper functions.

V3:
* Added WARN_ON_ONCE() if out of save states.
* Changed function interface of perf_sched_restore_state() to use bool
  as return value.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1321616122-1533-3-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:33:56 +01:00
Robert Richter
1e2ad28f80 perf, x86: Implement event scheduler helper functions
This patch introduces x86 perf scheduler code helper functions. We
need this to later add more complex functionality to support
overlapping counter constraints (next patch).

The algorithm is modified so that the range of weight values is now
generated from the constraints. There shouldn't be other functional
changes.

With the helper functions the scheduler is controlled. There are
functions to initialize, traverse the event list, find unused counters
etc. The scheduler keeps its own state.

V3:
* Added macro for_each_set_bit_cont().
* Changed functions interfaces of perf_sched_find_counter() and
  perf_sched_next_event() to use bool as return value.
* Added some comments to make code better understandable.

V4:
* Fix broken event assignment if weight of the first event is not
  wmin (perf_sched_init()).

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1321616122-1533-2-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:33:54 +01:00
Peter Zijlstra
0f5a260128 perf: Avoid a useless pmu_disable() in the perf-tick
Gleb writes:

 > Currently pmu is disabled and re-enabled on each timer interrupt even
 > when no rotation or frequency adjustment is needed. On Intel CPU this
 > results in two writes into PERF_GLOBAL_CTRL MSR per tick. On bare metal
 > it does not cause significant slowdown, but when running perf in a virtual
 > machine it leads to 20% slowdown on my machine.

Cure this by keeping a perf_event_context::nr_freq counter that counts the
number of active events that require frequency adjustments and use this in a
similar fashion to the already existing nr_events != nr_active test in
perf_rotate_context().

By being able to exclude both rotation and frequency adjustments a-priory for
the common case we can avoid the otherwise superfluous PMU disable.

Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-515yhoatehd3gza7we9fapaa@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:33:52 +01:00
Nicholas Bellinger
ddca8f3ed3 iscsi-target: Fix hex2bin warn_unused compile message
Fix the following compile warning with hex2bin() usage:

drivers/target/iscsi/iscsi_target_auth.c: In function ‘chap_string_to_hex’:
drivers/target/iscsi/iscsi_target_auth.c:35: warning: ignoring return value of ‘hex2bin’, declared with attribute warn_unused_result

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-12-06 06:00:59 +00:00
Andy Grover
c638830d04 target: Don't return an error if disabling unsupported features
If an attribute is present (but not yet supported) it should be OK
to write 0 (a no-op) to the attribute.

This is an issue because userspace should be able to save and restore all
set attribute values without error.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-12-06 06:00:58 +00:00
Sebastian Andrzej Siewior
65b0c78d5a target/rd: fix or rewrite the copy routine
So the code assumes that the sg list is only a array while in reality
loopback SGL memory via scsi_cmnd into target-core may be already
chained.  This patch converts ramdisk code to use sg_miter logic from
scatterlist.h in order to properly support passthrough SGL usage with
transport_generic_map_mem_to_cmd() via loopback.

With this patch the bug goes away. However after umount/mount of the
device my files are gone. So something is still not right. After looking
at it for a while I decided to rewrite the that part of the code and now
things do work for me.

For reference:
- http://article.gmane.org/gmane.linux.scsi.target.devel/595
  the sg_next() conversion
- http://article.gmane.org/gmane.linux.scsi.target.devel/602
  the rewrite of the copy code

(nab: Fix compile warning in rd_MEMCPY)

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-12-06 06:00:58 +00:00