1. 27 10月, 2010 1 次提交
  2. 19 10月, 2010 1 次提交
    • P
      irq_work: Add generic hardirq context callbacks · e360adbe
      Peter Zijlstra 提交于
      Provide a mechanism that allows running code in IRQ context. It is
      most useful for NMI code that needs to interact with the rest of the
      system -- like wakeup a task to drain buffers.
      
      Perf currently has such a mechanism, so extract that and provide it as
      a generic feature, independent of perf so that others may also
      benefit.
      
      The IRQ context callback is generated through self-IPIs where
      possible, or on architectures like powerpc the decrementer (the
      built-in timer facility) is set to generate an interrupt immediately.
      
      Architectures that don't have anything like this get to do with a
      callback from the timer tick. These architectures can call
      irq_work_run() at the tail of any IRQ handlers that might enqueue such
      work (like the perf IRQ handler) to avoid undue latencies in
      processing the work.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: NKyle McMartin <kyle@mcmartin.ca>
      Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      [ various fixes ]
      Signed-off-by: NHuang Ying <ying.huang@intel.com>
      LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e360adbe
  3. 05 10月, 2010 1 次提交
  4. 24 9月, 2010 1 次提交
    • R
      perf, x86: Catch spurious interrupts after disabling counters · 63e6be6d
      Robert Richter 提交于
      Some cpus still deliver spurious interrupts after disabling a
      counter. This caused 'undelivered NMI' messages. This patch
      fixes this. Introduced by:
      
        4177c42a: perf, x86: Try to handle unknown nmis with an enabled PMU
      Reported-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NRobert Richter <robert.richter@amd.com>
      Cc: Don Zickus <dzickus@redhat.com>
      Cc: gorcunov@gmail.com <gorcunov@gmail.com>
      Cc: fweisbec@gmail.com <fweisbec@gmail.com>
      Cc: ying.huang@intel.com <ying.huang@intel.com>
      Cc: ming.m.lin@intel.com <ming.m.lin@intel.com>
      Cc: yinghai@kernel.org <yinghai@kernel.org>
      Cc: andi@firstfloor.org <andi@firstfloor.org>
      Cc: eranian@google.com <eranian@google.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      LKML-Reference: <20100915162034.GO13563@erda.amd.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      63e6be6d
  5. 10 9月, 2010 6 次提交
    • P
      perf: Remove the sysfs bits · 15ac9a39
      Peter Zijlstra 提交于
      Neither the overcommit nor the reservation sysfs parameter were
      actually working, remove them as they'll only get in the way.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      15ac9a39
    • P
      perf: Rework the PMU methods · a4eaf7f1
      Peter Zijlstra 提交于
      Replace pmu::{enable,disable,start,stop,unthrottle} with
      pmu::{add,del,start,stop}, all of which take a flags argument.
      
      The new interface extends the capability to stop a counter while
      keeping it scheduled on the PMU. We replace the throttled state with
      the generic stopped state.
      
      This also allows us to efficiently stop/start counters over certain
      code paths (like IRQ handlers).
      
      It also allows scheduling a counter without it starting, allowing for
      a generic frozen state (useful for rotating stopped counters).
      
      The stopped state is implemented in two different ways, depending on
      how the architecture implemented the throttled state:
      
       1) We disable the counter:
          a) the pmu has per-counter enable bits, we flip that
          b) we program a NOP event, preserving the counter state
      
       2) We store the counter state and ignore all read/overflow events
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Michael Cree <mcree@orcon.net.nz>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a4eaf7f1
    • P
      perf: Per PMU disable · 33696fc0
      Peter Zijlstra 提交于
      Changes perf_disable() into perf_pmu_disable().
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Michael Cree <mcree@orcon.net.nz>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      33696fc0
    • P
      perf: Reduce perf_disable() usage · 24cd7f54
      Peter Zijlstra 提交于
      Since the current perf_disable() usage is only an optimization,
      remove it for now. This eases the removal of the __weak
      hw_perf_enable() interface.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Michael Cree <mcree@orcon.net.nz>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      24cd7f54
    • P
      perf: Register PMU implementations · b0a873eb
      Peter Zijlstra 提交于
      Simple registration interface for struct pmu, this provides the
      infrastructure for removing all the weak functions.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Michael Cree <mcree@orcon.net.nz>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      b0a873eb
    • P
      perf: Deconstify struct pmu · 51b0fe39
      Peter Zijlstra 提交于
      sed -ie 's/const struct pmu\>/struct pmu/g' `git grep -l "const struct pmu\>"`
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: paulus <paulus@samba.org>
      Cc: stephane eranian <eranian@googlemail.com>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Michael Cree <mcree@orcon.net.nz>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      51b0fe39
  6. 03 9月, 2010 1 次提交
    • R
      perf, x86: Try to handle unknown nmis with an enabled PMU · 4177c42a
      Robert Richter 提交于
      When the PMU is enabled it is valid to have unhandled nmis, two
      events could trigger 'simultaneously' raising two back-to-back
      NMIs. If the first NMI handles both, the latter will be empty
      and daze the CPU.
      
      The solution to avoid an 'unknown nmi' massage in this case was
      simply to stop the nmi handler chain when the PMU is enabled by
      stating the nmi was handled. This has the drawback that a) we
      can not detect unknown nmis anymore, and b) subsequent nmi
      handlers are not called.
      
      This patch addresses this. Now, we check this unknown NMI if it
      could be a PMU back-to-back NMI. Otherwise we pass it and let
      the kernel handle the unknown nmi.
      
      This is a debug log:
      
       cpu #6, nmi #32333, skip_nmi #32330, handled = 1, time = 1934364430
       cpu #6, nmi #32334, skip_nmi #32330, handled = 1, time = 1934704616
       cpu #6, nmi #32335, skip_nmi #32336, handled = 2, time = 1936032320
       cpu #6, nmi #32336, skip_nmi #32336, handled = 0, time = 1936034139
       cpu #6, nmi #32337, skip_nmi #32336, handled = 1, time = 1936120100
       cpu #6, nmi #32338, skip_nmi #32336, handled = 1, time = 1936404607
       cpu #6, nmi #32339, skip_nmi #32336, handled = 1, time = 1937983416
       cpu #6, nmi #32340, skip_nmi #32341, handled = 2, time = 1938201032
       cpu #6, nmi #32341, skip_nmi #32341, handled = 0, time = 1938202830
       cpu #6, nmi #32342, skip_nmi #32341, handled = 1, time = 1938443743
       cpu #6, nmi #32343, skip_nmi #32341, handled = 1, time = 1939956552
       cpu #6, nmi #32344, skip_nmi #32341, handled = 1, time = 1940073224
       cpu #6, nmi #32345, skip_nmi #32341, handled = 1, time = 1940485677
       cpu #6, nmi #32346, skip_nmi #32347, handled = 2, time = 1941947772
       cpu #6, nmi #32347, skip_nmi #32347, handled = 1, time = 1941949818
       cpu #6, nmi #32348, skip_nmi #32347, handled = 0, time = 1941951591
       Uhhuh. NMI received for unknown reason 00 on CPU 6.
       Do you have a strange power saving mode enabled?
       Dazed and confused, but trying to continue
      
      Deltas:
      
       nmi #32334 340186
       nmi #32335 1327704
       nmi #32336 1819      <<<< back-to-back nmi [1]
       nmi #32337 85961
       nmi #32338 284507
       nmi #32339 1578809
       nmi #32340 217616
       nmi #32341 1798      <<<< back-to-back nmi [2]
       nmi #32342 240913
       nmi #32343 1512809
       nmi #32344 116672
       nmi #32345 412453
       nmi #32346 1462095   <<<< 1st nmi (standard) handling 2 counters
       nmi #32347 2046      <<<< 2nd nmi (back-to-back) handling one
       counter nmi #32348 1773      <<<< 3rd nmi (back-to-back)
       handling no counter! [3]
      
      For  back-to-back nmi detection there are the following rules:
      
      The PMU nmi handler was handling more than one counter and no
      counter was handled in the subsequent nmi (see [1] and [2]
      above).
      
      There is another case if there are two subsequent back-to-back
      nmis [3]. The 2nd is detected as back-to-back because the first
      handled more than one counter. If the second handles one counter
      and the 3rd handles nothing, we drop the 3rd nmi because it
      could be a back-to-back nmi.
      Signed-off-by: NRobert Richter <robert.richter@amd.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      [ renamed nmi variable to pmu_nmi to avoid clash with .nmi in entry.S ]
      Signed-off-by: NDon Zickus <dzickus@redhat.com>
      Cc: peterz@infradead.org
      Cc: gorcunov@gmail.com
      Cc: fweisbec@gmail.com
      Cc: ying.huang@intel.com
      Cc: ming.m.lin@intel.com
      Cc: eranian@google.com
      LKML-Reference: <1283454469-1909-3-git-send-email-dzickus@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4177c42a
  7. 25 8月, 2010 1 次提交
    • L
      perf: Remove unused variable · 04fba671
      Lin Ming 提交于
      This fixes the following build warning introduced by the
      callchain rework:
      
        arch/x86/kernel/cpu/perf_event.c:1574: warning: ‘perf_callchain_entry_nmi’ defined but not used
      Signed-off-by: NLin Ming <ming.m.lin@intel.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1282718949.16443.75.camel@minggr.sh.intel.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      04fba671
  8. 20 8月, 2010 1 次提交
  9. 19 8月, 2010 5 次提交
    • F
      perf: Fix race in callchains · 927c7a9e
      Frederic Weisbecker 提交于
      Now that software events don't have interrupt disabled anymore in
      the event path, callchains can nest on any context. So seperating
      nmi and others contexts in two buffers has become racy.
      
      Fix this by providing one buffer per nesting level. Given the size
      of the callchain entries (2040 bytes * 4), we now need to allocate
      them dynamically.
      
      v2: Fixed put_callchain_entry call after recursion.
          Fix the type of the recursion, it must be an array.
      
      v3: Use a manual pr cpu allocation (temporary solution until NMIs
          can safely access vmalloc'ed memory).
          Do a better separation between callchain reference tracking and
          allocation. Make the "put" path lockless for non-release cases.
      
      v4: Protect the callchain buffers with rcu.
      
      v5: Do the cpu buffers allocations node affine.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Tested-by: NWill Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: David Miller <davem@davemloft.net>
      Cc: Borislav Petkov <bp@amd64.org>
      927c7a9e
    • F
      perf: Factorize callchain context handling · f72c1a93
      Frederic Weisbecker 提交于
      Store the kernel and user contexts from the generic layer instead
      of archs, this gathers some repetitive code.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: NPaul Mackerras <paulus@samba.org>
      Tested-by: NWill Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Borislav Petkov <bp@amd64.org>
      f72c1a93
    • F
      perf: Generalize some arch callchain code · 56962b44
      Frederic Weisbecker 提交于
      - Most archs use one callchain buffer per cpu, except x86 that needs
        to deal with NMIs. Provide a default perf_callchain_buffer()
        implementation that x86 overrides.
      
      - Centralize all the kernel/user regs handling and invoke new arch
        handlers from there: perf_callchain_user() / perf_callchain_kernel()
        That avoid all the user_mode(), current->mm checks and so...
      
      - Invert some parameters in perf_callchain_*() helpers: entry to the
        left, regs to the right, following the traditional (dst, src).
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: NPaul Mackerras <paulus@samba.org>
      Tested-by: NWill Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Borislav Petkov <bp@amd64.org>
      56962b44
    • F
      perf: Generalize callchain_store() · 70791ce9
      Frederic Weisbecker 提交于
      callchain_store() is the same on every archs, inline it in
      perf_event.h and rename it to perf_callchain_store() to avoid
      any collision.
      
      This removes repetitive code.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: NPaul Mackerras <paulus@samba.org>
      Tested-by: NWill Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Borislav Petkov <bp@amd64.org>
      70791ce9
    • F
      perf: Drop unappropriate tests on arch callchains · c1a65932
      Frederic Weisbecker 提交于
      Drop the TASK_RUNNING test on user tasks for callchains as
      this check doesn't seem to make any sense.
      
      Also remove the tests for !current that is not supposed to
      happen and current->pid as this should be handled at the
      generic level, with exclude_idle attribute.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Tested-by: NWill Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Borislav Petkov <bp@amd64.org>
      c1a65932
  10. 09 6月, 2010 5 次提交
    • P
      perf: Convert perf_event to local_t · e7850595
      Peter Zijlstra 提交于
      Since now all modification to event->count (and ->prev_count
      and ->period_left) are local to a cpu, change then to local64_t so we
      avoid the LOCK'ed ops.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e7850595
    • C
      perf, x86: Make a second write to performance counter if needed · 68aa00ac
      Cyrill Gorcunov 提交于
      On Netburst PMU we need a second write to a performance counter
      due to cpu erratum.
      
      A simple flag test instead of alternative instructions was choosen
      because wrmsrl is already a macro and if virtualization is turned
      on will need an additional wrapper call which is more expencise.
      
      nb: we should propably switch to jump-labels as only this facility
      reach the mainline.
      Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Lin Ming <ming.m.lin@intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20100602212304.GC5264@lenovo>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      68aa00ac
    • P
      perf: Cleanup {start,commit,cancel}_txn details · 8d2cacbb
      Peter Zijlstra 提交于
      Clarify some of the transactional group scheduling API details
      and change it so that a successfull ->commit_txn also closes
      the transaction.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1274803086.5882.1752.camel@twins>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      8d2cacbb
    • F
      perf: Drop the skip argument from perf_arch_fetch_regs_caller · b0f82b81
      Frederic Weisbecker 提交于
      Drop this argument now that we always want to rewind only to the
      state of the first caller.
      It means frame pointers are not necessary anymore to reliably get
      the source of an event. But this also means we need this helper
      to be a macro now, as an inline function is not an option since
      we need to know when to provide a default implentation.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Cc: David Miller <davem@davemloft.net>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      b0f82b81
    • F
      x86: Unify dumpstack.h and stacktrace.h · c9cf4dbb
      Frederic Weisbecker 提交于
      arch/x86/include/asm/stacktrace.h and arch/x86/kernel/dumpstack.h
      declare headers of objects that deal with the same topic.
      Actually most of the files that include stacktrace.h also include
      dumpstack.h
      
      Although dumpstack.h seems more reserved for internals of stack
      traces, those are quite often needed to define specialized stack
      trace operations. And perf event arch headers are going to need
      access to such low level operations anyway. So don't continue to
      bother with dumpstack.h as it's not anymore about isolated deep
      internals.
      
      v2: fix struct stack_frame definition conflict in sysprof
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Soeren Sandmann <sandmann@daimi.au.dk>
      c9cf4dbb
  11. 31 5月, 2010 1 次提交
    • S
      perf_events: Fix event scheduling issues introduced by transactional API · 90151c35
      Stephane Eranian 提交于
      The transactional API patch between the generic and model-specific
      code introduced several important bugs with event scheduling, at
      least on X86. If you had pinned events, e.g., watchdog,  and were
      over-committing the PMU, you would get bogus counts. The bug was
      showing up on Intel CPU because events would move around more
      often that on AMD. But the problem also existed on AMD, though
      harder to expose.
      
      The issues were:
      
       - group_sched_in() was missing a cancel_txn() in the error path
      
       - cpuc->n_added was not properly maintained, leading to missing
         actions in hw_perf_enable(), i.e., n_running being 0. You cannot
         update n_added until you know the transaction has succeeded. In
         case of failed transaction n_added was not adjusted back.
      
       - in case of failed transactions, event_sched_out() was called
         and eventually invoked x86_disable_event() to touch the HW reg.
         But with transactions, on X86, event_sched_in() does not touch
         HW registers, it simply collects events into a list. Thus, you
         could end up calling x86_disable_event() on a counter which
         did not correspond to the current event when idx != -1.
      
      The patch modifies the generic and X86 code to avoid all those problems.
      
      First, we keep track of the number of events added last. In case the
      transaction fails, we substract them from n_added. This approach is
      necessary (as opposed to delaying updates to n_added) because not all
      event updates use the transaction API, e.g., single events.
      
      Second, we encapsulate the event_sched_in() and event_sched_out() in
      group_sched_in() inside the transaction. That makes the operations
      symmetrical and you can also detect that you are inside a transaction
      and skip the HW reg access by checking cpuc->group_flag.
      
      With this patch, you can now overcommit the PMU even with pinned
      system-wide events present and still get valid counts.
      Signed-off-by: NStephane Eranian <eranian@google.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <1274796225.5882.1389.camel@twins>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      90151c35
  12. 25 5月, 2010 1 次提交
    • P
      perf, trace: Fix !x86 build bug · 87f44bbc
      Peter Zijlstra 提交于
      Patch b7e2ecef (perf, trace: Optimize tracepoints by removing
      IRQ-disable from perf/tracepoint interaction) made the
      unfortunate mistake of assuming the world is x86 only, correct
      this.
      
      The problem was that perf_fetch_caller_regs() did
      local_save_flags() into regs->flags, and I re-used that to
      remove another local_save_flags(), forgetting !x86 doesn't have
      regs->flags.
      
      Do the reverse, remove the local_save_flags() from
      perf_fetch_caller_regs() and let the ftrace site do the
      local_save_flags() instead.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Acked-by: NPaul Mackerras <paulus@samba.org>
      Cc: acme@redhat.com
      Cc: efault@gmx.de
      Cc: fweisbec@gmail.com
      Cc: rostedt@goodmis.org
      LKML-Reference: <1274778175.5882.623.camel@twins>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      87f44bbc
  13. 07 5月, 2010 7 次提交
  14. 20 4月, 2010 1 次提交
    • Z
      perf & kvm: Clean up some of the guest profiling callback API details · dcf46b94
      Zhang, Yanmin 提交于
      Fix some build bug and programming style issues:
      
       - use valid C
       - fix up various style details
      Signed-off-by: NZhang Yanmin <yanmin_zhang@linux.intel.com>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Sheng Yang <sheng@linux.intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: oerg Roedel <joro@8bytes.org>
      Cc: Jes Sorensen <Jes.Sorensen@redhat.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Cc: Zachary Amsden <zamsden@redhat.com>
      Cc: zhiteng.huang@intel.com
      Cc: tim.c.chen@intel.com
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      LKML-Reference: <1271729638.2078.624.camel@ymzhang.sh.intel.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      dcf46b94
  15. 19 4月, 2010 1 次提交
  16. 04 4月, 2010 1 次提交
  17. 03 4月, 2010 5 次提交