1. 22 8月, 2009 2 次提交
    • J
      time: Introduce CLOCK_REALTIME_COARSE · da15cfda
      john stultz 提交于
      After talking with some application writers who want very fast, but not
      fine-grained timestamps, I decided to try to implement new clock_ids
      to clock_gettime(): CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE
      which returns the time at the last tick. This is very fast as we don't
      have to access any hardware (which can be very painful if you're using
      something like the acpi_pm clocksource), and we can even use the vdso
      clock_gettime() method to avoid the syscall. The only trade off is you
      only get low-res tick grained time resolution.
      
      This isn't a new idea, I know Ingo has a patch in the -rt tree that made
      the vsyscall gettimeofday() return coarse grained time when the
      vsyscall64 sysctrl was set to 2. However this affects all applications
      on a system.
      
      With this method, applications can choose the proper speed/granularity
      trade-off for themselves.
      Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: nikolag@ca.ibm.com
      Cc: Darren Hart <dvhltc@us.ibm.com>
      Cc: arjan@infradead.org
      Cc: jonathan@jonmasters.org
      LKML-Reference: <1250734414.6897.5.camel@localhost.localdomain>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      da15cfda
    • T
      x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown · 8cab02dc
      Thomas Gleixner 提交于
      This basically reverts commit 1a0c009a (x86: unregister PIT
      clocksource when PIT is disabled) because the problem which was tried
      to address with that patch has been solved by commit 3f68535a
      (clocksource: sanity check sysfs clocksource changes).
      
      The problem addressed by the original patch is that PIT could be
      selected as clocksource after the system switched the PIT off or set
      the PIT into one shot mode which would result in complete timekeeping
      wreckage.
      
      Now with the sysfs sanity check in place PIT cannot be selected again
      when the system is in oneshot mode. The system will not switch to one
      shot mode as long as PIT is installed because PIT is not suitable for
      one shot.
      
      The shutdown case which happens when the lapic timer is installed is
      covered by the fact that init_pit_clocksource() is called after the
      lapic timer take over and then does not install the PIT clocksource
      at all.
      
      We should have done the sanity checks back then, but ...
      
      This also solves the locking problem which was reported vs. the
      clocksource rework.
      
      LKML-Reference: <new-submission>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: john stultz <johnstul@us.ibm.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      8cab02dc
  2. 19 8月, 2009 2 次提交
    • M
      clocksource: Avoid clocksource watchdog circular locking dependency · 01548f4d
      Martin Schwidefsky 提交于
      stop_machine from a multithreaded workqueue is not allowed because
      of a circular locking dependency between cpu_down and the workqueue
      execution. Use a kernel thread to do the clocksource downgrade.
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: john stultz <johnstul@us.ibm.com>
      LKML-Reference: <20090818170942.3ab80c91@skybase>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      01548f4d
    • T
      clocksource: Protect the watchdog rating changes with clocksource_mutex · d0981a1b
      Thomas Gleixner 提交于
      Martin pointed out that commit 6ea41d2529 (clocksource: Call
      clocksource_change_rating() outside of watchdog_lock) has a
      theoretical reference count problem. The calls to
      clocksource_change_rating() are now done outside of the clocksource
      mutex and outside of the watchdog lock. A concurrent
      clocksource_unregister() could remove the clock.
      
      Split out the code which changes the rating from
      clocksource_change_rating() into __clocksource_change_rating().
      
      Protect the clocksource_watchdog_work() code sequence with the
      clocksource_mutex() and call __clocksource_change_rating().
      
      LKML-Reference: <alpine.LFD.2.00.0908171038420.2782@localhost.localdomain>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      d0981a1b
  3. 15 8月, 2009 16 次提交
  4. 14 8月, 2009 10 次提交
  5. 13 8月, 2009 10 次提交
    • P
      perf_counter: Report the cloning task as parent on perf_counter_fork() · 94d5d1b2
      Peter Zijlstra 提交于
      A bug in (9f498cc5: perf_counter: Full task tracing) makes
      profiling multi-threaded apps it go belly up.
      
      [ output as: (PID:TID):(PPID:PTID) ]
      
       # ./perf report -D | grep FORK
      0x4b0 [0x18]: PERF_EVENT_FORK: (3237:3237):(3236:3236)
      0xa10 [0x18]: PERF_EVENT_FORK: (3237:3238):(3236:3236)
      0xa70 [0x18]: PERF_EVENT_FORK: (3237:3239):(3236:3236)
      0xad0 [0x18]: PERF_EVENT_FORK: (3237:3240):(3236:3236)
      0xb18 [0x18]: PERF_EVENT_FORK: (3237:3241):(3236:3236)
      
      Shows us that the test (27d028de perf report: Update for the new
      FORK/EXIT events) in builtin-report.c:
      
              /*
               * A thread clone will have the same PID for both
               * parent and child.
               */
              if (thread == parent)
                      return 0;
      
      Will clearly fail.
      
      The problem is that perf_counter_fork() reports the actual
      parent, instead of the cloning thread.
      
      Fixing that (with the below patch), yields:
      
       # ./perf report -D | grep FORK
      0x4c8 [0x18]: PERF_EVENT_FORK: (1590:1590):(1589:1589)
      0xbd8 [0x18]: PERF_EVENT_FORK: (1590:1591):(1590:1590)
      0xc80 [0x18]: PERF_EVENT_FORK: (1590:1592):(1590:1590)
      0x3338 [0x18]: PERF_EVENT_FORK: (1590:1593):(1590:1590)
      0x66b0 [0x18]: PERF_EVENT_FORK: (1590:1594):(1590:1590)
      
      Which both makes more sense and doesn't confuse perf report
      anymore.
      Reported-by: NPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: paulus@samba.org
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Arjan van de Ven <arjan@infradead.org>
      LKML-Reference: <1250172882.5241.62.camel@twins>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      94d5d1b2
    • P
      perf_counter: Fix an ipi-deadlock · 970892a9
      Peter Zijlstra 提交于
      perf_pending_counter() is called from IRQ context and will call
      perf_counter_disable(), however perf_counter_disable() uses
      smp_call_function_single() which doesn't fancy being used with
      IRQs disabled due to IPI deadlocks.
      
      Fix this by making it use the local __perf_counter_disable()
      call and teaching the counter_sched_out() code about pending
      disables as well.
      
      This should cover the case where a counter migrates before the
      pending queue gets processed.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Corey J Ashford <cjashfor@us.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      LKML-Reference: <20090813103655.244097721@chello.nl>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      970892a9
    • P
      perf: Rework/fix the whole read vs group stuff · 3dab77fb
      Peter Zijlstra 提交于
      Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce
      PERF_FORMAT_GROUP to deal with group reads in a more generic
      way.
      
      This allows you to get group reads out of read() as well.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Corey J Ashford <cjashfor@us.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      LKML-Reference: <20090813103655.117411814@chello.nl>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3dab77fb
    • P
      perf_counter: Fix swcounter context invariance · bcfc2602
      Peter Zijlstra 提交于
      perf_swcounter_is_counting() uses a lock, which means we cannot
      use swcounters from NMI or when holding that particular lock,
      this is unintended.
      
      The below removes the lock, this opens up race window, but not
      worse than the swcounters already experience due to RCU
      traversal of the context in perf_swcounter_ctx_event().
      
      This also fixes the hard lockups while opening a lockdep
      tracepoint counter.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Corey J Ashford <cjashfor@us.ibm.com>
      LKML-Reference: <1250149915.10001.66.camel@twins>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      bcfc2602
    • A
      perf report: Don't show unresolved DSOs and symbols when -S/-d is used · 8fd101f2
      Arnaldo Carvalho de Melo 提交于
      We're interested in just those symbols/DSOs, so filter out the
      unresolved ones.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      LKML-Reference: <20090812211957.GE3495@ghostprotocols.net>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      8fd101f2
    • F
      perf tools: Add a general option to enable raw sample records · daac07b2
      Frederic Weisbecker 提交于
      While we can enable the perf sample records per tracepoint
      counter, we may also want to enable this option for every
      tracepoint counters to open, so that we don't need to add a
      :record flag for all of them.
      
      Add the -R, --raw-samples options for this purpose.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Mike Galbraith <efault@gmx.de>
      LKML-Reference: <1250152039-7284-2-git-send-email-fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      daac07b2
    • F
      perf tools: Add a per tracepoint counter attribute to get raw sample · 3a9f131f
      Frederic Weisbecker 提交于
      Add a new flag field while opening a tracepoint perf counter:
      
      	-e tracepoint_subsystem:tracepoint_name:flags
      
      This is intended to be generic although for now it only supports the
      r[e[c[o[r[d]]]]] flag:
      
      	./perf record -e workqueue:workqueue_insertion:record
      	./perf record -e workqueue:workqueue_insertion:r
      
      will have the same effect: enabling the raw samples record for
      the given tracepoint counter.
      
      In the future, we may want to support further flags, separated
      by commas.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Mike Galbraith <efault@gmx.de>
      LKML-Reference: <1250152039-7284-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3a9f131f
    • I
      perf_counter: Provide hw_perf_counter_setup_online() APIs · 28402971
      Ingo Molnar 提交于
      Provide weak aliases for hw_perf_counter_setup_online(). This is
      used by the BTS patches (for v2.6.32), but it interacts with
      fixes so propagate this upstream. (it has no effect as of yet)
      
      Also export perf_counter_output() to architecture code.
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      28402971
    • A
      perf list: Fix large list output by using the pager · 8f7a0dc5
      Arnaldo Carvalho de Melo 提交于
      When /sys/kernel/debug is mounted the list can be imense, so
      use the pager like the other tools.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      LKML-Reference: <20090812174459.GB3495@ghostprotocols.net>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      8f7a0dc5
    • M
      sh: fix i2c init order on ap325rxa V2 · dbefd606
      Magnus Damm 提交于
      Convert the AP325RXA board code to register devices at
      arch_initcall() time instead of device_initcall(). This
      fix unbreaks pcf8563 RTC driver support.
      Signed-off-by: NMagnus Damm <damm@igel.co.jp>
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      dbefd606