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  1. 25 Mar, 2011 1 commit
    • Ingo Molnar's avatar
      perf, x86: Complain louder about BIOSen corrupting CPU/PMU state and continue · 45daae57
      Ingo Molnar authored 
      Eric Dumazet reported that hardware PMU events do not work on his
system, due to the BIOS corrupting PMU state:

    Performance Events: PEBS fmt0+, Core2 events, Broken BIOS detected, using software events only.
    [Firmware Bug]: the BIOS has corrupted hw-PMU resources (MSR 186 is 43003c)

Linus suggested that we continue in the face of such BIOS-induced CPU
state corruption:

   http://lkml.org/lkml/2011/3/24/608

Such BIOSes will have to be fixed - Linux developers rely on a working and
fully capable PMU and the BIOS interfering with the CPU's PMU state is simply
not acceptable.

So this patch changes perf to continue when it detects such BIOS
interaction, some hardware events may be unreliable due to the BIOS
writing and re-writing them - there's not much the kernel can do
about that but to detect the corruption and report it.
Reported-and-tested-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      45daae57
  3. 24 Mar, 2011 1 commit
    • Don Zickus's avatar
      perf, x86: P4 PMU - Read proper MSR register to catch unflagged overflows · 242214f9
      Don Zickus authored 
      The read of a proper MSR register was missed and instead of
counter the configration register was tested (it has
ARCH_P4_UNFLAGGED_BIT always cleared) leading to unknown NMI
hitting the system. As result the user may obtain "Dazed and
confused, but trying to continue" message. Fix it by reading a
proper MSR register.

When an NMI happens on a P4, the perf nmi handler checks the
configuration register to see if the overflow bit is set or not
before taking appropriate action.  Unfortunately, various P4
machines had a broken overflow bit, so a backup mechanism was
implemented.  This mechanism checked to see if the counter
rolled over or not.

A previous commit that implemented this backup mechanism was
broken. Instead of reading the counter register, it used the
configuration register to determine if the counter rolled over
or not. Reading that bit would give incorrect results.

This would lead to 'Dazed and confused' messages for the end
user when using the perf tool (or if the nmi watchdog is
running).

The fix is to read the counter register before determining if
the counter rolled over or not.
Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Signed-off-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <4D8BAB49.3080701@openvz.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      242214f9
  5. 23 Mar, 2011 7 commits
    • Arnaldo Carvalho de Melo's avatar
      perf symbols: Look at .dynsym again if .symtab not found · 60e4b10c
      Arnaldo Carvalho de Melo authored 
      The original intent of the code was to repeat the search with
want_symtab = 0. But as the code stands now, we never hit the "default"
case of the switch statement. Which means we never repeat the search.
Tested-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: default avatarArun Sharma <asharma@fb.com>
Reported-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Dave Martin <dave.martin@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      60e4b10c
    • Arnaldo Carvalho de Melo's avatar
      perf build-id: Add quirk to deal with perf.data file format breakage · b2511481
      Arnaldo Carvalho de Melo authored 
      The a1645ce1 changeset:

"perf: 'perf kvm' tool for monitoring guest performance from host"

Added a field to struct build_id_event that broke the file format.

Since the kernel build-id is the first entry, process the table using
the old format if the well known '[kernel.kallsyms]' string for the
kernel build-id has the first 4 characters chopped off (where the pid_t
sits).
Reported-by: default avatarHan Pingtian <phan@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Cc: stable@kernel.org
LKML-Reference: <new-submission>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2511481
    • Arnaldo Carvalho de Melo's avatar
      perf session: Pass evsel in event_ops->sample() · 9e69c210
      Arnaldo Carvalho de Melo authored 
      Resolving the sample->id to an evsel since the most advanced tools,
report and annotate, and the others will too when they evolve to
properly support multi-event perf.data files.

Good also because it does an extra validation, checking that the ID is
valid when present. When that is not the case, the overhead is just a
branch + function call (perf_evlist__id2evsel).

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      9e69c210
    • Frederic Weisbecker's avatar
      perf: Better fit max unprivileged mlock pages for tools needs · 880f5731
      Frederic Weisbecker authored 
      The maximum kilobytes of locked memory that an unprivileged user
can reserve is of 512 kB = 128 pages by default, scaled to the
number of onlined CPUs, which fits well with the tools that use
128 data pages by default.

However tools actually use 129 pages, because they need one more
for the user control page. Thus the default mlock threshold is
not sufficient for the default tools needs and we always end up
to evaluate the constant mlock rlimit policy, which doesn't have
this scaling with the number of online CPUs.

Hence, on systems that have more than 16 CPUs, we overlap the
rlimit threshold and fail to mmap:

	$ perf record ls
	Error: failed to mmap with 1 (Operation not permitted)

Just increase the max unprivileged mlock threshold by one page
so that it supports well perf tools even after 16 CPUs.
Reported-by: default avatarHan Pingtian <phan@redhat.com>
Reported-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stable <stable@kernel.org>
LKML-Reference: <1300904979-5508-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      880f5731
    • Stephane Eranian's avatar
      perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx() · 68cacd29
      Stephane Eranian authored 
      This patch solves a stale pointer problem in
update_cgrp_time_from_cpuctx(). The cpuctx->cgrp
was not cleared on all possible event exit paths,
including:

   close()
     perf_release()
       perf_release_kernel()
         list_del_event()

This patch fixes list_del_event() to clear cpuctx->cgrp
when there are no cgroup events left in the context.

[ This second version makes the code compile when
  CONFIG_CGROUP_PERF is not enabled. We unconditionally define
  perf_cpu_context->cgrp. ]
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: perfmon2-devel@lists.sf.net
Cc: paulus@samba.org
Cc: davem@davemloft.net
LKML-Reference: <20110323150306.GA1580@quad>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      68cacd29
    • Akihiro Nagai's avatar
      perf top: Fix uninitialized 'counter' variable · ce2d17ca
      Akihiro Nagai authored 
      builtin-top.c has an uninitialized variable.
gcc(version 4.5.1) warns about it and it results in build failure:

 builtin-top.c: In function 'display_thread':
 builtin-top.c:518:9: error: 'counter' may be used uninitialized

This situation can indeed trigger, if the getline() call in
prompt_integer() fails.
Signed-off-by: default avatarAkihiro Nagai <akihiro.nagai.hw@hitachi.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110323072939.11638.50173.stgit@localhost6.localdomain6>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ce2d17ca
    • Ingo Molnar's avatar
      Merge branch 'tip/perf/urgent' of... · e1eb0290
      Ingo Molnar authored 
      Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
      e1eb0290
  7. 22 Mar, 2011 1 commit
    • Jiri Olsa's avatar
      tracing: Fix set_ftrace_filter probe function display · 1106b699
      Jiri Olsa authored 
      If one or more function probes (like traceon) are enabled,
and there's no other function filter, the first probe
func is skipped (which one depends on the position in the hash).

$ echo sys_open:traceon sys_close:traceon > ./set_ftrace_filter
$ cat set_ftrace_filter
#### all functions enabled ####
sys_close:traceon:unlimited
$

The reason was, that in the case of no other function filter,
the func_pos was not properly updated before calling t_hash_start.
Signed-off-by: default avatarJiri Olsa <jolsa@redhat.com>
LKML-Reference: <1297874134-7008-1-git-send-email-jolsa@redhat.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      1106b699
  9. 19 Mar, 2011 1 commit
    • Stephane Eranian's avatar
      perf, x86: Fix Intel fixed counters base initialization · fc66c521
      Stephane Eranian authored 
      The following patch solves the problems introduced by Robert's
commit 41bf4989 and reported by Arun Sharma. This commit gets rid
of the base + index notation for reading and writing PMU msrs.

The problem is that for fixed counters, the new calculation for
the base did not take into account the fixed counter indexes,
thus all fixed counters were read/written from fixed counter 0.
Although all fixed counters share the same config MSR, they each
have their own counter register.

Without:

 $ task -e unhalted_core_cycles -e instructions_retired -e baclears noploop 1 noploop for 1 seconds

  242202299 unhalted_core_cycles (0.00% scaling, ena=1000790892, run=1000790892)
 2389685946 instructions_retired (0.00% scaling, ena=1000790892, run=1000790892)
      49473 baclears             (0.00% scaling, ena=1000790892, run=1000790892)

With:

 $ task -e unhalted_core_cycles -e instructions_retired -e baclears noploop 1 noploop for 1 seconds

 2392703238 unhalted_core_cycles (0.00% scaling, ena=1000840809, run=1000840809)
 2389793744 instructions_retired (0.00% scaling, ena=1000840809, run=1000840809)
      47863 baclears             (0.00% scaling, ena=1000840809, run=1000840809)
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: ming.m.lin@intel.com
Cc: robert.richter@amd.com
Cc: asharma@fb.com
Cc: perfmon2-devel@lists.sf.net
LKML-Reference: <20110319172005.GB4978@quad>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      fc66c521
  11. 18 Mar, 2011 1 commit
  13. 17 Mar, 2011 3 commits
  15. 16 Mar, 2011 25 commits
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