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Update rcutorture documentation to account for boosting, new types of
RCU torture testing that have been added over the past few years, and
the memory-barrier testing that was added an embarrassingly long time
ago.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Take a first step towards untangling Linux kernel header files by
placing the struct rcu_head definition into include/linux/types.h
and including include/linux/types.h in include/linux/rcupdate.h
where struct rcu_head used to be defined. The actual inclusion point
for include/linux/types.h is with the rest of the #include directives
rather than at the point where struct rcu_head used to be defined,
as suggested by Mathieu Desnoyers.
Once this is in place, then header files that need only rcu_head
can include types.h rather than rcupdate.h.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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Long ago, using TREE_RCU with PREEMPT would result in "scheduling
while atomic" diagnostics if you blocked in an RCU read-side critical
section. However, PREEMPT now implies TREE_PREEMPT_RCU, which defeats
this diagnostic. This commit therefore adds a replacement diagnostic
based on PROVE_RCU.
Because rcu_lockdep_assert() and lockdep_rcu_dereference() are now being
used for things that have nothing to do with rcu_dereference(), rename
lockdep_rcu_dereference() to lockdep_rcu_suspicious() and add a third
argument that is a string indicating what is suspicious. This third
argument is passed in from a new third argument to rcu_lockdep_assert().
Update all calls to rcu_lockdep_assert() to add an informative third
argument.
Also, add a pair of rcu_lockdep_assert() calls from within
rcu_note_context_switch(), one complaining if a context switch occurs
in an RCU-bh read-side critical section and another complaining if a
context switch occurs in an RCU-sched read-side critical section.
These are present only if the PROVE_RCU kernel parameter is enabled.
Finally, fix some checkpatch whitespace complaints in lockdep.c.
Again, you must enable PROVE_RCU to see these new diagnostics. But you
are enabling PROVE_RCU to check out new RCU uses in any case, aren't you?
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Call out the RCU_TRACE information that is provided only in kernels
built with RCU_BOOST.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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There are a number of cases where the RCU can find additional work
for the per-CPU kthread within the context of that per-CPU kthread.
In such cases, the per-CPU kthread is already running, so attempting
to wake itself up does nothing except waste CPU cycles. This commit
therefore checks to see if it is in the per-CPU kthread context,
omitting the wakeup in this case.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Commit a26ac2455ffc (move TREE_RCU from softirq to kthread) added
per-CPU kthreads. However, kthread creation uses kthread_create(), which
can put the kthread's stack and task struct on the wrong NUMA node.
Therefore, use kthread_create_on_node() instead of kthread_create()
so that the stacks and task structs are placed on the correct NUMA node.
A similar change was carried out in commit 94dcf29a11b3 (kthread:
use kthread_create_on_node()).
Also change rcutorture's priority-boost-test kthread creation.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tejun Heo <tj@kernel.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Andi Kleen <ak@linux.intel.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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* 'for-linus' of git://github.com/tiwai/sound:
ASoC: ssm2602: Re-enable oscillator after suspend
ALSA: usb-audio: Check for possible chip NULL pointer before clearing probing flag
ALSA: hda/realtek - Don't detect LO jack when identical with HP
ALSA: hda/realtek - Avoid bogus HP-pin assignment
ALSA: HDA: No power nids on 92HD93
ASoC: omap-mcbsp: Do not attempt to change DAI sysclk if stream is active
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* 'pm-fixes' of git://github.com/rjwysocki/linux-pm:
PM / Clocks: Do not acquire a mutex under a spinlock
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That flag no longer makes sense, since we don't look up automount points
as eagerly any more. Additionally, it turns out that the NO_AUTOMOUNT
handling was buggy to begin with: it would avoid automounting even for
cases where we really *needed* to do the automount handling, and could
return ENOENT for autofs entries that hadn't been instantiated yet.
With our new non-eager automount semantics, one discussion has been
about adding a AT_AUTOMOUNT flag to vfs_fstatat (and thus the
newfstatat() and fstatat64() system calls), but it's probably not worth
it: you can always force at least directory automounting by simply
adding the final '/' to the filename, which works for *all* of the stat
family system calls, old and new.
So AT_NO_AUTOMOUNT (and thus LOOKUP_NO_AUTOMOUNT) really were just a
result of our bad default behavior.
Acked-by: Ian Kent <raven@themaw.net>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently the the internal oscillator is powered down when entering BIAS_OFF
state, but not re-enabled when going back to BIAS_STANDBY. As a result the
CODEC will stop working after suspend if the internal oscillator is used to
generate the sysclock signal. This patch fixes it by clearing the appropriate
bit in the power down register when the CODEC is re-enabled.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
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The concensus seems to be that system calls such as stat() etc should
not trigger an automount. Neither should the l* versions.
This patch therefore adds a LOOKUP_AUTOMOUNT flag to tag those lookups
that _should_ trigger an automount on the last path element.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ Edited to leave out the cases that are already covered by LOOKUP_OPEN,
LOOKUP_DIRECTORY and LOOKUP_CREATE - all of which also fundamentally
force automounting for their own reasons - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since we've now turned around and made LOOKUP_FOLLOW *not* force an
automount, we want to add the ability to force an automount event on
lookup even if we don't happen to have one of the other flags that force
it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..)
Most cases will never want to use this, since you'd normally want to
delay automounting as long as possible, which usually implies
LOOKUP_OPEN (when we open a file or directory, we really cannot avoid
the automount any more).
But Trond argued sufficiently forcefully that at a minimum bind mounting
a file and quotactl will want to force the automount lookup. Some other
cases (like nfs_follow_remote_path()) could use it too, although
LOOKUP_DIRECTORY would work there as well.
This commit just adds the flag and logic, no users yet, though. It also
doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and
was made irrelevant by the same change that made us not follow on
LOOKUP_FOLLOW.
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* 'samsung-fixes-3' of git://github.com/kgene/linux-samsung:
ARM: EXYNOS4: Rename sclk_cam clocks for FIMC driver
ARM: S5PV210: Rename sclk_cam clocks for FIMC media driver
ARM: S5P: fix incorrect loop iterator usage on gpio-interrupt
ARM: S3C2443: Fix bit-reset in setrate of clk_armdiv
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The sclk_cam clocks are now controlled by the top level FIMC media
device driver bound to "s5p-fimc-md" platform device.
Rename sclk_cam clocks so they accessible by the corresponding
driver.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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The sclk_cam clocks are now controlled by the top level FIMC media
device driver bound to "s5p-fimc-md" platform device.
Rename sclk_cam clocks so they accessible by the corresponding
driver.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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* 'hwmon-for-linus' of git://github.com/groeck/linux:
hwmon: (coretemp) remove struct platform_data * parameter from create_core_data()
hwmon: (coretemp) constify static data
hwmon: (coretemp) don't use kernel assigned CPU number as platform device ID
hwmon: (ds620) Fix handling of negative temperatures
hwmon: (w83791d) rename prototype parameter from 'register' to 'reg'
hwmon: (coretemp) Don't use threshold registers for tempX_max
hwmon: (coretemp) Let the user force TjMax
hwmon: (coretemp) Drop duplicate function get_pkg_tjmax
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* 'kvm-updates/3.1' of git://github.com/avikivity/kvm:
KVM: x86 emulator: fix Src2CL decode
KVM: MMU: fix incorrect return of spte
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http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm:
ARM: 7099/1: futex: preserve oldval in SMP __futex_atomic_op
ARM: dma-mapping: free allocated page if unable to map
ARM: fix vmlinux.lds.S discarding sections
ARM: nommu: fix warning with checksyscalls.sh
ARM: 7091/1: errata: D-cache line maintenance operation by MVA may not succeed
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Commit b7ab83e (PM: Use spinlock instead of mutex in clock
management functions) introduced a regression causing clocks_mutex
to be acquired under a spinlock. This happens because
pm_clk_suspend() and pm_clk_resume() call pm_clk_acquire() under
pcd->lock, but pm_clk_acquire() executes clk_get() which causes
clocks_mutex to be acquired. Similarly, __pm_clk_remove(),
executed under pcd->lock, calls clk_put(), which also causes
clocks_mutex to be acquired.
To fix those problems make pm_clk_add() call pm_clk_acquire(), so
that pm_clk_suspend() and pm_clk_resume() don't have to do that.
Change pm_clk_remove() and pm_clk_destroy() to separate
modifications of the pcd->clock_list list from the actual removal of
PM clock entry objects done by __pm_clk_remove().
Reported-and-tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
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probing flag
Before clearing the probing flag in the error exit path, check that the
chip pointer is not NULL.
Signed-off-by: Thomas Pfaff <tpfaff@gmx.net>
Cc: <stable@kernel.org> [2.6.39+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The spec->autocfg.line_out_pins[] may contain the same pins as hp_pins[]
depending on the configuration. When they are identical, detecting the
line_jack_present flag screws up the auto-mute because alc_line_automute()
is called unconditionally at initialization while it won't be triggered
by unsol events, thus the old line_jack_present flag is kept for the
whole run.
For fixing this buggy behavior, the driver needs to check whether the
line-outs are really individual, and skip if same as headphone jacks.
Reference: https://bugzilla.novell.com/show_bug.cgi?id=716104
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The SMP implementation of __futex_atomic_op clobbers oldval with the
status flag from the exclusive store. This causes it to always read as
zero when performing the FUTEX_OP_CMP_* operation.
This patch updates the ARM __futex_atomic_op implementations to take a
tmp argument, allowing us to store the strex status flag without
overwriting the register containing oldval.
Cc: stable@kernel.org
Reported-by: Minho Ban <mhban@samsung.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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When the headphone pin is assigned as primary output to line_out_pins[],
the automatic HP-pin assignment by ASSID must be suppressed. Otherwise
a wrong pin might be assigned to the headphone and breaks the auto-mute.
Reference: https://bugzilla.novell.com/show_bug.cgi?id=716104
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>
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If the attempt to map a page for DMA fails (eg, because we're out of
mapping space) then we must not hold on to the page we allocated for
DMA - doing so will result in a memory leak.
Cc: <stable@kernel.org>
Reported-by: Bryan Phillippe <bp@darkforest.org>
Tested-by: Bryan Phillippe <bp@darkforest.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Loop iterator value after terminating list_for_each_entry()
is not NULL. This patch fixes incorrect iterator usage in
GPIO interrupt code for SAMSUNG S5P platforms.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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The changed statement should set the old armdiv bits to 0
and not everything else, before setting the new value.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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If PTRACE_LISTEN fails after lock_task_sighand() it doesn't drop ->siglock.
Reported-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Src2CL decode (used for double width shifts) erronously decodes only bit 3
of %rcx, instead of bits 7:0.
Fix by decoding %cl in its entirety.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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__update_clear_spte_slow should return original spte while the
current code returns low half of original spte combined with high
half of new spte.
Signed-off-by: Zhao Jin <cronozhj@gmail.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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This patch is necessary to make internal speakers work on this chip.
Cc: stable@kernel.org
BugLink: http://bugs.launchpad.net/bugs/854468
Tested-by: Alex Wolfson <alex.wolfson@canonical.com>
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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* 'spi/merge' of git://git.secretlab.ca/git/linux-2.6:
spi: Fix WARN when removing spi-fsl-spi module
spi/imx: Fix spi-imx when the hardware SPI chipselects are used
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If CPM mode is not used, the fsl_dummy_rx variable is never allocated. When
the cleanup attempts to free it, the reference count is zero and a WARN is
generated. The same CPM mode check used in the initialize is applied to the
free as well.
Tested on 2.6.33 with the previous spi_mpc8xxx driver. The renamed
spi-fsl-spi driver looks to have the same problem.
Signed-off-by: Jeff Harris <jeff_harris@kentrox.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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sector_t can be different types, so cast it to its largest possible
type.
drivers/scsi/qla2xxx/qla_isr.c:1509:5: warning: format '%lx' expects type 'long unsigned int', but argument 5 has type 'sector_t'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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SCSI_ISCI needs to select SCSI_SAS_HOST_SMP to ensure that all
needed symbols are available to it.
Fixes this build error:
ERROR: "try_test_sas_gpio_gp_bit" [drivers/scsi/isci/isci.ko] undefined!
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* 'perf-tools-for-linus' of git://github.com/acmel/linux:
perf python: Add missing perf_event__parse_sample 'swapped' parm
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* 'perf-tools-for-linus' of git://github.com/acmel/linux:
perf tools: Add support for disabling -Werror via WERROR=0
perf top: Fix userspace sample addr map offset
perf symbols: Fix issue with binaries using 16-bytes buildids (v2)
perf tool: Fix endianness handling of u32 data in samples
perf sort: Fix symbol sort output by separating unresolved samples by type
perf symbols: Synthesize anonymous mmap events
perf record: Create events initially disabled and enable after init
perf symbols: Add some heuristics for choosing the best duplicate symbol
perf symbols: Preserve symbol scope when parsing /proc/kallsyms
perf symbols: /proc/kallsyms does not sort module symbols
perf symbols: Fix ppc64 SEGV in dso__load_sym with debuginfo files
perf probe: Fix regression of variable finder
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* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon/kms: fix DDIA enable on some rs690 systems
Revert "drm/radeon/kms: fix typo in r100_blit_copy"
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* 'for-linus' of git://github.com/tiwai/sound:
ALSA: usb-audio - clear chip->probing on error exit
ALSA: fm801: Gracefully handle failure of tuner auto-detect
ALSA: fm801: Fix double free in case of error in tuner detection
ASoC: Ensure we generate a driver name
ASoC: Remove bitrotted wm8962_resume()
ASoC: bf5xx-ad73311: Fix prototype for bf5xx_probe
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Problem introduced in 936be50, that missed one perf_event__parse_sample
user, the python binding.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ja4phms9618ggi657plyuch2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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create_core_data()
The only caller of the function obtained the pointer solely for the
purpose of passing it to this function, while it can be easily
determined from the struct platform_device * parameter also passed.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
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These arrays won't ever be written to, so protect them from
unintentional modification.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
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... as that has the potential to conflict with (particularly soft) CPU
hot removal and re-adding.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
[guenter.roeck@ericsson.com: use platform device ID as physical CPU id]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
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GCC often introduces new warnings with lots of false positives -
breaking -Werror builds. WERROR=0 allows one to build perf without much
fuss - while still encouraging people to send patches to avoid the fuss
of having to type WERROR=0.
Bisecting back to commits that produce a (mostly harmless) warning on
some compilers is more difficult. With WERROR=0 one could bisect without
worrying about harmless warnings.
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/eac06c7cc4920e5d4830417d466161fb26c7359c.1315514559.git.dvhart@linux.intel.com
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The 'perf top' tool came from the kernel where we had each DSO (vmlinux,
modules) loaded just once at a time.
But userspace may have DSOs loaded in multiple addresses (shared
libraries), requiring that we use the just resolved map instead of the
first one found.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ag53wz0yllpgers0n2w7hchp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Buildid can vary in size. According to the man page of ld, buildid can
be 160 bits (sha1) or 128 bits (md5, uuid). Perf assumes buildid size of
20 bytes (160 bits) regardless. When dealing with md5 buildids, it would
thus read more than needed and that would cause mismatches and samples
without symbols.
This patch fixes this by taking into account the actual buildid size as
encoded int he section header. The leftover bytes are also cleared.
This second version fixes a minor issue with the memset() base position.
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@gmail.com>
Link: http://lkml.kernel.org/r/4cc1af3c.8ee7d80a.5a28.ffff868e@mx.google.com
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Currently, analyzing PPC data files on x86 the cpu field is always 0 and
the tid and pid are backwards. For example, analyzing a PPC file on PPC
the pid/tid fields show:
rsyslogd 1210/1212
and analyzing the same PPC file using an x86 perf binary shows:
rsyslogd 1212/1210
The problem is that the swap_op method for samples is
perf_event__all64_swap which assumes all elements in the sample_data
struct are u64s. cpu, tid and pid are u32s and need to be handled
individually. Given that the swap is done before the sample is parsed,
the simplest solution is to undo the 64-bit swap of those elements when
the sample is parsed and do the proper swap.
The RAW data field is generic and perf cannot have programmatic knowledge
of how to treat that data. Instead a warning is given to the user.
Thanks to Anton Blanchard for providing a data file for a mult-CPU
PPC system so I could verify the fix for the CPU fields.
v3 -> v4:
- fixed use of WARN_ONCE
v2 -> v3:
- used WARN_ONCE for message regarding raw data
- removed struct wrapper around union
- fixed whitespace issues
v1 -> v2:
- added a union for undoing the byte-swap on u64 and redoing swap on
u32's to address compiler errors (see git commit 65014ab3)
Cc: Anton Blanchard <anton@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1315321946-16993-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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I took a profile that suggested 60% of total CPU time was in the
hypervisor:
...
60.20% [H] 0x33d43c
4.43% [k] ._spin_lock_irqsave
1.07% [k] ._spin_lock
Using perf stat to get the user/kernel/hypervisor breakdown contradicted
this.
The problem is we merge all unresolved samples into the one unknown
bucket. If add a comparison by sample type to sort__sym_cmp we get the
real picture:
...
57.11% [.] 0x80fbf63c
4.43% [k] ._spin_lock_irqsave
1.07% [k] ._spin_lock
0.65% [H] 0x33d43c
So it was almost all userspace, not hypervisor as the initial profile
suggested.
I found another issue while adding this. Symbol sorting sometimes shows
multiple entries for the unknown bucket:
...
16.65% [.] 0x6cd3a8
7.25% [.] 0x422460
5.37% [.] yylex
4.79% [.] malloc
4.78% [.] _int_malloc
4.03% [.] _int_free
3.95% [.] hash_source_code_string
2.82% [.] 0x532908
2.64% [.] 0x36b538
0.94% [H] 0x8000000000e132a4
0.82% [H] 0x800000000000e8b0
This happens because we aren't consistent with our sorting. On
one hand we check to see if both symbols match and for two unresolved
samples sym is NULL so we match:
if (left->ms.sym == right->ms.sym)
return 0;
On the other hand we use sample IP for unresolved samples when
comparing against a symbol:
ip_l = left->ms.sym ? left->ms.sym->start : left->ip;
ip_r = right->ms.sym ? right->ms.sym->start : right->ip;
This means unresolved samples end up spread across the rbtree and we
can't merge them all.
If we use cmp_null all unresolved samples will end up in the one bucket
and the output makes more sense:
...
39.12% [.] 0x36b538
5.37% [.] yylex
4.79% [.] malloc
4.78% [.] _int_malloc
4.03% [.] _int_free
3.95% [.] hash_source_code_string
2.26% [H] 0x800000000000e8b0
Acked-by: Eric B Munson <emunson@mgebm.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Link: http://lkml.kernel.org/r/20110831115145.4f598ab2@kryten
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
perf_event__synthesize_mmap_events does not create anonymous mmap events
even though the kernel does. As a result an already running application
with dynamically created code will not get profiled - all samples end up
in the unknown bucket.
This patch skips any entries with '[' in the name to avoid adding events
for special regions (eg the vsyscall page). All other executable mmaps
are assumed to be anonymous and an event is synthesized.
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Link: http://lkml.kernel.org/r/20110830091506.60b51fe8@kryten
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
