1. 20 May, 2009 2 commits
    • Peter Zijlstra's avatar
      perf_counter: Log irq_period changes · 26b119bc
      Peter Zijlstra authored
      For the dynamic irq_period code, log whenever we change the period so that
      analyzing code can normalize the event flow.
      
      [ Impact: add new feature to allow more precise profiling ]
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: John Kacur <jkacur@redhat.com>
      LKML-Reference: <20090520102553.298769743@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      26b119bc
    • Peter Zijlstra's avatar
      perf_counter: Solve the rotate_ctx vs inherit race differently · d7b629a3
      Peter Zijlstra authored
      Instead of disabling RR scheduling of the counters, use a different list
      that does not get rotated to iterate the counters on inheritance.
      
      [ Impact: cleanup, optimization ]
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: John Kacur <jkacur@redhat.com>
      LKML-Reference: <20090520102553.237504544@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d7b629a3
  2. 19 May, 2009 2 commits
  3. 18 May, 2009 3 commits
    • Ingo Molnar's avatar
      perf_counter, x86: speed up the scheduling fast-path · b68f1d2e
      Ingo Molnar authored
      We have to set up the LVT entry only at counter init time, not at
      every switch-in time.
      
      There's friction between NMI and non-NMI use here - we'll probably
      remove the per counter configurability of it - but until then, dont
      slow down things ...
      
      [ Impact: micro-optimization ]
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b68f1d2e
    • Paul Mackerras's avatar
      perf_counter: powerpc: initialize cpuhw pointer before use · c0daaf3f
      Paul Mackerras authored
      Commit 9e35ad38 ("perf_counter: Rework the perf counter
      disable/enable") added code to the powerpc hw_perf_enable (renamed
      from hw_perf_restore) to test cpuhw->disabled and return immediately
      if it is not set (i.e. if the PMU is already enabled).
      
      Unfortunately the test got added before cpuhw was initialized,
      resulting in an oops the first time hw_perf_enable got called.
      This fixes it by moving the initialization of cpuhw to before
      cpuhw->disabled is tested.
      
      [ Impact: fix oops-causing bug on powerpc ]
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      LKML-Reference: <18960.56772.869734.304631@drongo.ozlabs.ibm.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c0daaf3f
    • Ingo Molnar's avatar
      Merge commit 'v2.6.30-rc6' into perfcounters/core · dc3f81b1
      Ingo Molnar authored
      Merge reason: this branch was on an -rc4 base, merge it up to -rc6
                    to get the latest upstream fixes.
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      dc3f81b1
  4. 17 May, 2009 4 commits
    • Ingo Molnar's avatar
      perf_counter, x86: fix zero irq_period counters · d2517a49
      Ingo Molnar authored
      The quirk to irq_period unearthed an unrobustness we had in the
      hw_counter initialization sequence: we left irq_period at 0, which
      was then quirked up to 2 ... which then generated a _lot_ of
      interrupts during 'perf stat' runs, slowed them down and skewed
      the counter results in general.
      
      Initialize irq_period to the maximum instead.
      
      [ Impact: fix perf stat results ]
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d2517a49
    • Ingo Molnar's avatar
      perf_counter: fix threaded task exit · 0203026b
      Ingo Molnar authored
      Flushing counters in __exit_signal() with irqs disabled is not
      a good idea as perf_counter_exit_task() acquires mutexes. So
      flush it before acquiring the tasklist lock.
      
      (Note, we still need a fix for when the PID has been unhashed.)
      
      [ Impact: fix crash with inherited counters ]
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      0203026b
    • Peter Zijlstra's avatar
      perf_counter: Fix counter inheritance · 856d56b9
      Peter Zijlstra authored
      Srivatsa Vaddagiri reported that a Java workload triggers this
      warning in kernel/exit.c:
      
         WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list));
      
      Add the inherited counter propagation on self-detach, this could
      cause counter leaks and incomplete stats in threaded code like
      the below:
      
        #include <pthread.h>
        #include <unistd.h>
      
        void *thread(void *arg)
        {
                sleep(5);
                return NULL;
        }
      
        void main(void)
        {
                pthread_t thr;
                pthread_create(&thr, NULL, thread, NULL);
        }
      Reported-by: default avatarSrivatsa Vaddagiri <vatsa@in.ibm.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      856d56b9
    • Peter Zijlstra's avatar
      perf_counter: Fix inheritance cleanup code · 8bc20959
      Peter Zijlstra authored
      Clean up code that open-coded the list_{add,del}_counter() code in
      __perf_counter_exit_task() which consequently diverged. This could
      lead to software counter crashes.
      
      Also, fold the ctx->nr_counter inc/dec into those functions and clean
      up some of the related code.
      
      [ Impact: fix potential sw counter crash, cleanup ]
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      8bc20959
  5. 16 May, 2009 1 commit
  6. 15 May, 2009 28 commits