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  1. 21 Jan, 2011 3 commits
    • Han Pingtian's avatar
      perf test: Use cpu_map->[cpu] when setting affinity · ffb5e0fb
      Han Pingtian authored 
      When some of CPUs are offline:

 # cat /sys/devices/system/cpu/online
 0,6-31

perf test will fail on #3 testcase:

   3: detect open syscall event on all cpus:
   --- start ---
   perf_evsel__read_on_cpu: expected to intercept 111 calls on cpu 0, got 681
   perf_evsel__read_on_cpu: expected to intercept 112 calls on cpu 1, got 117
   perf_evsel__read_on_cpu: expected to intercept 113 calls on cpu 2, got 118
   perf_evsel__read_on_cpu: expected to intercept 114 calls on cpu 3, got 119
   perf_evsel__read_on_cpu: expected to intercept 115 calls on cpu 4, got 120
   perf_evsel__read_on_cpu: expected to intercept 116 calls on cpu 5, got 121
   perf_evsel__read_on_cpu: expected to intercept 117 calls on cpu 6, got 122
   perf_evsel__read_on_cpu: expected to intercept 118 calls on cpu 7, got 123
   perf_evsel__read_on_cpu: expected to intercept 119 calls on cpu 8, got 124
   perf_evsel__read_on_cpu: expected to intercept 120 calls on cpu 9, got 125
   perf_evsel__read_on_cpu: expected to intercept 121 calls on cpu 10, got 126
   ....

This patch try to use 'cpus->map[cpu]' when setting cpu affinity, and
will check the return code of sched_setaffinity()

LKML-Reference: <20110120114707.GA11781@hpt.nay.redhat.com>
Signed-off-by: default avatarHan Pingtian <phan@redhat.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ffb5e0fb
    • Dr. David Alan Gilbert's avatar
      perf symbols: Fix annotation of thumb code · b2f8fb23
      Dr. David Alan Gilbert authored 
      In ARM's Thumb mode the bottom bit of the symbol address is set to mark
the function as Thumb; the instructions are in reality 2 or 4 byte on 2
byte alignments, and when the +1 address is used in annotate it causes
objdump to disassemble invalid instructions.

The patch removes that bottom bit during symbol loading.

Many thinks to Dave Martin for comments on an initial version of the
patch.

(For reference this corresponds to this bug
https://bugs.launchpad.net/linux-linaro/+bug/677547 )

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Martin <dave.martin@linaro.org>
LKML-Reference: <20110121163922.GA31398@davesworkthinkpad>
Signed-off-by: default avatarDr. David Alan Gilbert <david.gilbert@linaro.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2f8fb23
    • Peter Zijlstra's avatar
      perf: Annotate cpuctx->ctx.mutex to avoid a lockdep splat · 547e9fd7
      Peter Zijlstra authored 
      Lockdep spotted:

	loop_1b_instruc/1899 is trying to acquire lock:
	 (event_mutex){+.+.+.}, at: [<ffffffff810e1908>] perf_trace_init+0x3b/0x2f7

	but task is already holding lock:
	 (&ctx->mutex){+.+.+.}, at: [<ffffffff810eb45b>] perf_event_init_context+0xc0/0x218

	which lock already depends on the new lock.

	the existing dependency chain (in reverse order) is:

	-> #3 (&ctx->mutex){+.+.+.}:
	-> #2 (cpu_hotplug.lock){+.+.+.}:
	-> #1 (module_mutex){+.+...}:
	-> #0 (event_mutex){+.+.+.}:

But because the deadlock would be cpuhotplug (cpu-event) vs fork
(task-event) it cannot, in fact, happen. We can annotate this by giving the
perf_event_context used for the cpuctx a different lock class from those
used by tasks.
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      547e9fd7
  3. 19 Jan, 2011 3 commits
    • Anton Blanchard's avatar
      powerpc, perf: Fix frequency calculation for overflowing counters (FSL version) · 8c8a9b25
      Anton Blanchard authored 
      When fixing the frequency calculations for perf on powerpc I
forgot to fix the FSL version.

If we dont set event->hw.last_period the frequency to period
calculations in perf go haywire and we continually
throttle/unthrottle the PMU.
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110118214404.2f42e634@kryten>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      8c8a9b25
    • Oleg Nesterov's avatar
      perf: Fix perf_event_init_task()/perf_event_free_task() interaction · 8550d7cb
      Oleg Nesterov authored 
      perf_event_init_task() should clear child->perf_event_ctxp[]
before anything else. Otherwise, if
perf_event_init_context(perf_hw_context) fails,
perf_event_free_task() can free perf_event_ctxp[perf_sw_context]
copied from parent->perf_event_ctxp[] by dup_task_struct().

Also move the initialization of perf_event_mutex and
perf_event_list from perf_event_init_context() to
perf_event_init_context().
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <20110119182228.GC12183@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      8550d7cb
    • Oleg Nesterov's avatar
      perf: Fix find_get_context() vs perf_event_exit_task() race · dbe08d82
      Oleg Nesterov authored 
      find_get_context() must not install the new perf_event_context
if the task has already passed perf_event_exit_task().

If nothing else, this means the memory leak. Initially
ctx->refcount == 2, it is supposed that
perf_event_exit_task_context() should participate and do the
necessary put_ctx().

find_lively_task_by_vpid() checks PF_EXITING but this buys
nothing, by the time we call find_get_context() this task can be
already dead. To the point, cmpxchg() can succeed when the task
has already done the last schedule().

Change find_get_context() to populate task->perf_event_ctxp[]
under task->perf_event_mutex, this way we can trust PF_EXITING
because perf_event_exit_task() takes the same mutex.

Also, change perf_event_exit_task_context() to use
rcu_dereference(). Probably this is not strictly needed, but
with or without this change find_get_context() can race with
setup_new_exec()->perf_event_exit_task(), rcu_dereference()
looks better.
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <20110119182207.GB12183@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      dbe08d82
  5. 18 Jan, 2011 34 commits
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