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  1. Jun 18, 2012
    • Yan, Zheng's avatar
      perf: Avoid race between cpu hotplug and installing event · fbfc623f
      Yan, Zheng authored 
      

perf_event_open() requires the cpu on which to install event is online,
but the cpu can go offline after perf_event_open checks that. Add a
get_online_cpus()/put_online_cpus() pair to avoid the race.

Signed-off-by: default avatarZheng Yan <zheng.z.yan@intel.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1339741902-8449-3-git-send-email-zheng.z.yan@intel.com
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      fbfc623f
    • Yan, Zheng's avatar
      perf: Export perf_assign_events() · 4b4969b1
      Yan, Zheng authored 
      

Export perf_assign_events() so the uncore code can use it to
schedule events.

Signed-off-by: default avatarZheng Yan <zheng.z.yan@intel.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1339741902-8449-2-git-send-email-zheng.z.yan@intel.com
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4b4969b1
    • Ingo Molnar's avatar
      Merge branch 'perf/urgent' into perf/core · d1ece099
      Ingo Molnar authored 
      

Merge in all fixes before applying more changes.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      d1ece099
    • Salman Qazi's avatar
      perf: Use css_tryget() to avoid propping up css refcount · 9c5da09d
      Salman Qazi authored 
      

An rmdir pushes css's ref count to zero.  However, if the associated
directory is open at the time, the dentry ref count is non-zero.  If
the fd for this directory is then passed into perf_event_open, it
does a css_get().  This bounces the ref count back up from zero.  This
is a problem by itself.  But what makes it turn into a crash is the
fact that we end up doing an extra dput, since we perform a dput
when css_put sees the ref count go down to zero.

css_tryget() does not fall into that trap. So, we use that instead.

Reproduction test-case for the bug:

 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <linux/unistd.h>
 #include <linux/perf_event.h>
 #include <string.h>
 #include <errno.h>
 #include <stdio.h>

 #define PERF_FLAG_PID_CGROUP    (1U << 2)

 int perf_event_open(struct perf_event_attr *hw_event_uptr,
                     pid_t pid, int cpu, int group_fd, unsigned long flags) {
         return syscall(__NR_perf_event_open,hw_event_uptr, pid, cpu,
                 group_fd, flags);
 }

 /*
  * Directly poke at the perf_event bug, since it's proving hard to repro
  * depending on where in the kernel tree.  what moved?
  */
 int main(int argc, char **argv)
 {
        int fd;
        struct perf_event_attr attr;
        memset(&attr, 0, sizeof(attr));
        attr.exclude_kernel = 1;
        attr.size = sizeof(attr);
        mkdir("/dev/cgroup/perf_event/blah", 0777);
        fd = open("/dev/cgroup/perf_event/blah", O_RDONLY);
        perror("open");
        rmdir("/dev/cgroup/perf_event/blah");
        sleep(2);
        perf_event_open(&attr, fd, 0, -1,  PERF_FLAG_PID_CGROUP);
        perror("perf_event_open");
        close(fd);
        return 0;
 }

Signed-off-by: default avatarSalman Qazi <sqazi@google.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20120614223108.1025.2503.stgit@dungbeetle.mtv.corp.google.com
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9c5da09d
    • Robert Richter's avatar
      perf/x86/amd: Fix RDPMC index calculation for AMD family 15h · 76958a61
      Robert Richter authored 
      

The RDPMC index calculation is wrong for AMD family 15h
(X86_FEATURE_ PERFCTR_CORE set). This leads to a #GP when
accessing the counter:

 Pid: 2237, comm: syslog-ng Not tainted 3.5.0-rc1-perf-x86_64-standard-g130ff90 #135 AMD Pike/Pike
 RIP: 0010:[<ffffffff8100dc33>]  [<ffffffff8100dc33>] x86_perf_event_update+0x27/0x66

While the msr address offset is (index << 1) we must use index to
select the correct rdpmc.

Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      76958a61
    • Ingo Molnar's avatar
      Merge branch 'tip/perf/core' of... · 4983955c
      Ingo Molnar authored 
      
Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

Pull ftrace robustization fixes from Steve Rostedt.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4983955c
  3. Jun 16, 2012
  5. Jun 15, 2012
    • Steven Rostedt's avatar
      tracing: Register the ftrace internal events during early boot · 7374e827
      Steven Rostedt authored 
      

All trace events including ftrace internel events (like trace_printk
and function tracing), register functions that describe how to print
their output. The events may be recorded as soon as the ring buffer
is allocated, but they are just raw binary in the buffer. The mapping
of event ids to how to print them are held within a structure that
is registered on system boot.

If a crash happens in boot up before these functions are registered
then their output (via ftrace_dump_on_oops) will be useless:

Dumping ftrace buffer:
---------------------------------
   <...>-1       0.... 319705us : Unknown type 6
---------------------------------

This can be quite frustrating for a kernel developer trying to see
what is going wrong.

There's no reason to register them so late in the boot up process.
They can be registered by early_initcall().

Reported-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      7374e827
    • Steven Rostedt's avatar
      tracing: Add comments for the other bits of ftrace_event_call.flags · 5da43bed
      Steven Rostedt authored 
      

	TRACE_EVENT_FL_ENABLED_BIT,
	TRACE_EVENT_FL_FILTERED_BIT,
	TRACE_EVENT_FL_RECORDED_CMD_BIT,

Have comments about what they are, but:

	TRACE_EVENT_FL_CAP_ANY_BIT,
	TRACE_EVENT_FL_NO_SET_FILTER_BIT,
	TRACE_EVENT_FL_IGNORE_ENABLE_BIT,

do not, making them second class citizens. To prevent another
class warfare, these bits have protested for their right to be
commented. And By Golly! I'll give them what they want!

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      5da43bed
    • Borislav Petkov's avatar
      ftrace: Remove a superfluous check · 8d240dd8
      Borislav Petkov authored 
      

register_ftrace_function() checks ftrace_disabled and calls
__register_ftrace_function which does it again.

Drop the first check and add the unlikely hint to the second one. Also,
drop the label as John correctly notices.

No functional change.

Link: http://lkml.kernel.org/r/20120329171140.GE6409@aftab

Cc: Borislav Petkov <bp@amd64.org>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: default avatarBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      8d240dd8
  7. Jun 14, 2012
    • Don Zickus's avatar
      watchdog: Quiet down the boot messages · a7027046
      Don Zickus authored 
      

A bunch of bugzillas have complained how noisy the nmi_watchdog
is during boot-up especially with its expected failure cases
(like virt and bios resource contention).

This is my attempt to quiet them down and keep it less confusing
for the end user.  What I did is print the message for cpu0 and
save it for future comparisons.  If future cpus have an
identical message as cpu0, then don't print the redundant info.
However, if a future cpu has a different message, happily print
that loudly.

Before the change, you would see something like:

    ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
    CPU0: Intel(R) Core(TM)2 Quad CPU    Q9550  @ 2.83GHz stepping 0a
    Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver.
    ... version:                2
    ... bit width:              40
    ... generic registers:      2
    ... value mask:             000000ffffffffff
    ... max period:             000000007fffffff
    ... fixed-purpose events:   3
    ... event mask:             0000000700000003
    NMI watchdog enabled, takes one hw-pmu counter.
    Booting Node   0, Processors  #1
    NMI watchdog enabled, takes one hw-pmu counter.
     #2
    NMI watchdog enabled, takes one hw-pmu counter.
     #3 Ok.
    NMI watchdog enabled, takes one hw-pmu counter.
    Brought up 4 CPUs
    Total of 4 processors activated (22607.24 BogoMIPS).

After the change, it is simplified to:

    ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
    CPU0: Intel(R) Core(TM)2 Quad CPU    Q9550  @ 2.83GHz stepping 0a
    Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver.
    ... version:                2
    ... bit width:              40
    ... generic registers:      2
    ... value mask:             000000ffffffffff
    ... max period:             000000007fffffff
    ... fixed-purpose events:   3
    ... event mask:             0000000700000003
    NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
    Booting Node   0, Processors  #1 #2 #3 Ok.
    Brought up 4 CPUs

V2: little changes based on Joe Perches' feedback
V3: printk cleanup based on Ingo's feedback; checkpatch fix
V4: keep printk as one long line
V5: Ingo fix ups

Reported-and-tested-by: default avatarNathan Zimmer <nzimmer@sgi.com>
Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Cc: nzimmer@sgi.com
Cc: joe@perches.com
Link: http://lkml.kernel.org/r/1339594548-17227-1-git-send-email-dzickus@redhat.com
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a7027046
  9. Jun 13, 2012
  11. Jun 12, 2012
    • Arnaldo Carvalho de Melo's avatar
      perf tools: Fix synthesizing tracepoint names from the perf.data headers · cb9dd49e
      Arnaldo Carvalho de Melo authored 
      

We need to use the per event info snapshoted at record time to
synthesize the events name, so do it just after reading the perf.data
headers, when we already processed the /sys events data, otherwise we'll
end up using the local /sys that only by sheer luck will have the same
tracepoint ID -> real event association.

Example:

  # uname -a
  Linux felicio.ghostprotocols.net 3.4.0-rc5+ #1 SMP Sat May 19 15:27:11 BRT 2012 x86_64 x86_64 x86_64 GNU/Linux
  # perf record -e sched:sched_switch usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.015 MB perf.data (~648 samples) ]
  # cat /t/events/sched/sched_switch/id
  279
  # perf evlist -v
  sched:sched_switch: sample_freq=1, type: 2, config: 279, size: 80, sample_type: 1159, read_format: 7, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1
  #

So on the above machine the sched:sched_switch has tracepoint id 279, but on
the machine were we'll analyse it it has a different id:

  $ cat /t/events/sched/sched_switch/id
  56
  $ perf evlist -i /tmp/perf.data
  kmem:mm_balancedirty_writeout
  $ cat /t/events/kmem/mm_balancedirty_writeout/id
  279

With this fix:

  $ perf evlist -i /tmp/perf.data
  sched:sched_switch

Reported-by: default avatarDmitry Antipov <dmitry.antipov@linaro.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
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-auwks8fpuhmrdpiefs55o5oz@git.kernel.org
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      cb9dd49e
  13. Jun 11, 2012
    • Stephane Eranian's avatar
      perf stat: Fix default output file · fc3e4d07
      Stephane Eranian authored 
      The following commit:

commit 56f3bae7


Author: Jim Cromie <jim.cromie@gmail.com>
Date:   Wed Sep 7 17:14:00 2011 -0600

    perf stat: Add --log-fd <N> option to redirect stderr elsewhere

introduced a bug in the way perf stat outputs the results by default,
i.e., without the --log-fd or --output option. It would default to
writing to file descriptor 0, i.e., stdin. Writing to stdin is allowed
and is equivalent to writing to stdout. However, there is a major
difference for any script that was already capturing the output of perf
stat via redirection:

    perf stat >/tmp/log .... or perf stat 2>/tmp/log ....

They would not capture anything anymore. They would have to do:
    perf stat 0>/tmp/log ...

This breaks compatibility with existing scripts and does not look very
natural.

This patch fixes the problem by looking at output_fd only when it was
modified by user (> 0). It also checks that the value if positive.
Passing --log-fd 0 is ignored.

I would also argue that defaulting to stderr for the results is not the
right thing to do, though this patch does not address this specific
issue.

Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jim Cromie <jim.cromie@gmail.com>
Link: http://lkml.kernel.org/r/20120515111111.GA9870@quad
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      fc3e4d07
    • David Ahern's avatar
      perf tools: Fix endianity swapping for adds_features bitmask · 80c0120a
      David Ahern authored 
      

Based on Jiri's latest attempt:
https://lkml.org/lkml/2012/5/16/61

Basically, adds_features should be byte swapped assuming unsigned
longs are either 8-bytes (u64) or 4-bytes (u32).

    Fixes 32-bit ppc dumping 64-bit x86 feature data:
     ========
     captured on: Sun May 20 19:23:23 2012
     hostname : nxos-vdc-dev3
     os release : 3.4.0-rc7+
     perf version : 3.4.rc4.137.g978da3
     arch : x86_64
     nrcpus online : 16
     nrcpus avail : 16
     cpudesc : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
     cpuid : GenuineIntel,6,26,5
     total memory : 24680324 kB
    ...

Verified 64-bit x86 can still dump feature data for 32-bit ppc.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Reviewed-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4FBBB539.5010805@gmail.com
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      80c0120a
    • Shuah Khan's avatar
      perf/x86: Convert obsolete simple_strtoul() usage to kstrtoul() · e2b297fc
      Shuah Khan authored 
      

Signed-off-by: default avatarShuah Khan <shuahkhan@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1339384421.3025.8.camel@lorien2
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      e2b297fc
    • Ingo Molnar's avatar
      Merge tag 'v3.5-rc2' into perf/core · c3e228d5
      Ingo Molnar authored 
      

Merge in Linux 3.5-rc2 - to pick up fixes.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      c3e228d5
  15. Jun 09, 2012
    • Linus Torvalds's avatar
      Linux 3.5-rc2 · cfaf0251
      Linus Torvalds authored
      v3.5-rc2
      cfaf0251
    • David Rientjes's avatar
      mm, oom: fix badness score underflow · 1e11ad8d
      David Rientjes authored 
      If the privileges given to root threads (3% of allowable memory) or a
negative value of /proc/pid/oom_score_adj happen to exceed the amount of
rss of a thread, its badness score overflows as a result of commit
a7f638f9

 ("mm, oom: normalize oom scores to oom_score_adj scale only
for userspace").

Fix this by making the type signed and return 1, meaning the thread is
still eligible for kill, if the value is negative.

Reported-by: default avatarDave Jones <davej@redhat.com>
Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1e11ad8d
    • Linus Torvalds's avatar
      Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 72494504
      Linus Torvalds authored 
      Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix the relax_domain_level boot parameter
  sched: Validate assumptions in sched_init_numa()
  sched: Always initialize cpu-power
  sched: Fix domain iteration
  sched/rt: Fix lockdep annotation within find_lock_lowest_rq()
  sched/numa: Load balance between remote nodes
  sched/x86: Calculate booted cores after construction of sibling_mask
      72494504
    • Randy Dunlap's avatar
      sched/fair: fix lots of kernel-doc warnings · cd96891d
      Randy Dunlap authored 
      

Fix lots of new kernel-doc warnings in kernel/sched/fair.c:

  Warning(kernel/sched/fair.c:3625): No description found for parameter 'env'
  Warning(kernel/sched/fair.c:3625): Excess function parameter 'sd' description in 'update_sg_lb_stats'
  Warning(kernel/sched/fair.c:3735): No description found for parameter 'env'
  Warning(kernel/sched/fair.c:3735): Excess function parameter 'sd' description in 'update_sd_pick_busiest'
  Warning(kernel/sched/fair.c:3735): Excess function parameter 'this_cpu' description in 'update_sd_pick_busiest'
  .. more warnings

Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cd96891d
    • Linus Torvalds's avatar
      Revert "drm/i915/crt: Do not rely upon the HPD presence pin" · 8f53369b
      Linus Torvalds authored 
      This reverts commit 9e612a00

.

It incorrectly finds VGA connectors where none are attached, apparently
not noticing that nothing replied to the EDID queries, and happily using
the default EDID modes that have nothing to do with actual hardware.

That in turn then causes X to fall down to the lowest common
denominator, which is usually the default 1024x768 mode that is in the
default EDID and pretty much anything supports).

I'd suggest that if not relying on the HDP pin, the code should at least
check whether it gets valid EDID data back, rather than just assume
there's something on the VGA connector.

Cc: Dave Airlie <airlied@linux.ie>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8f53369b
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 77249539
      Linus Torvalds authored 
      Pull ext4 bug fixes from Theodore Ts'o:
 "This update contains two bug fixes, both destined for the stable tree.
  Perhaps the most important is one which fixes ext4 when used with file
  systems originally formatted for use with ext3, but then later
  converted to take advantage of ext4."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: don't set i_flags in EXT4_IOC_SETFLAGS
  ext4: fix the free blocks calculation for ext3 file systems w/ uninit_bg
      77249539
    • Linus Torvalds's avatar
      Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc · 3e9ca022
      Linus Torvalds authored 
      Pull powerpc fixes from Paul Mackerras:
 "Two small fixes for powerpc:
   - a fix for a regression since 3.2 that causes 4-second (or longer)
     pauses
   - a fix for a potential oops when loading kernel modules on 32-bit
     embedded systems."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  powerpc: Fix kernel panic during kernel module load
  powerpc/time: Sanity check of decrementer expiration is necessary
      3e9ca022
    • Linus Torvalds's avatar
      Merge tag 'upstream-3.5-rc2' of git://git.infradead.org/linux-ubifs · e7264308
      Linus Torvalds authored 
      Pull UBI/UBIFS fixes from Artem Bityutskiy:
 "Fix UBI and UBIFS - they refuse to work without debugfs.  This was
  broken by the 3.5-rc1 UBI/UBIFS changes when we removed the debugging
  Kconfig switches.

  Also, correct locking in 'ubi_wl_flush()' - it was extended to support
  flushing a specific LEB in 3.5-rc1, and the locking was sub-optimal."

* tag 'upstream-3.5-rc2' of git://git.infradead.org/linux-ubifs:
  UBI: correct ubi_wl_flush locking
  UBIFS: fix debugfs-less systems support
  UBI: fix debugfs-less systems support
      e7264308