1. 02 Apr, 2015 32 commits
    • Stephane Eranian's avatar
      perf/x86: Add 'index' param to get_event_constraint() callback · 79cba822
      Stephane Eranian authored
      
      
      This patch adds an index parameter to the get_event_constraint()
      x86_pmu callback. It is expected to represent the index of the
      event in the cpuc->event_list[] array. When the callback is used
      for fake_cpuc (evnet validation), then the index must be -1. The
      motivation for passing the index is to use it to index into another
      cpuc array.
      Signed-off-by: default avatarStephane Eranian <eranian@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: bp@alien8.de
      Cc: jolsa@redhat.com
      Cc: kan.liang@intel.com
      Cc: maria.n.dimakopoulou@gmail.com
      Link: http://lkml.kernel.org/r/1416251225-17721-5-git-send-email-eranian@google.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      79cba822
    • Maria Dimakopoulou's avatar
      perf/x86: Add 3 new scheduling callbacks · c5362c0c
      Maria Dimakopoulou authored
      
      
      This patch adds 3 new PMU model specific callbacks
      during the event scheduling done by x86_schedule_events().
      
        ->start_scheduling():  invoked when entering the schedule routine.
        ->stop_scheduling():   invoked at the end of the schedule routine
        ->commit_scheduling(): invoked for each committed event
      
      To be used optionally by model-specific code.
      Signed-off-by: default avatarMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Reviewed-by: default avatarStephane Eranian <eranian@google.com>
      Cc: bp@alien8.de
      Cc: jolsa@redhat.com
      Cc: kan.liang@intel.com
      Link: http://lkml.kernel.org/r/1416251225-17721-4-git-send-email-eranian@google.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      c5362c0c
    • Stephane Eranian's avatar
      perf/x86: Vectorize cpuc->kfree_on_online · 90413464
      Stephane Eranian authored
      
      
      Make the cpuc->kfree_on_online a vector to accommodate
      more than one entry and add the second entry to be
      used by a later patch.
      Signed-off-by: default avatarStephane Eranian <eranian@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Reviewed-by: default avatarMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
      Cc: bp@alien8.de
      Cc: jolsa@redhat.com
      Cc: kan.liang@intel.com
      Link: http://lkml.kernel.org/r/1416251225-17721-3-git-send-email-eranian@google.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      90413464
    • Stephane Eranian's avatar
      perf/x86: Rename x86_pmu::er_flags to 'flags' · 9a5e3fb5
      Stephane Eranian authored
      
      
      Because it will be used for more than just tracking the
      presence of extra registers.
      Signed-off-by: default avatarStephane Eranian <eranian@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: bp@alien8.de
      Cc: jolsa@redhat.com
      Cc: kan.liang@intel.com
      Cc: maria.n.dimakopoulou@gmail.com
      Link: http://lkml.kernel.org/r/1416251225-17721-2-git-send-email-eranian@google.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      9a5e3fb5
    • Ingo Molnar's avatar
    • Alexander Shishkin's avatar
      perf/x86/intel/bts: Add BTS PMU driver · 8062382c
      Alexander Shishkin authored
      
      
      Add support for Branch Trace Store (BTS) via kernel perf event infrastructure.
      The difference with the existing implementation of BTS support is that this
      one is a separate PMU that exports events' trace buffers to userspace by means
      of AUX area of the perf buffer, which is zero-copy mapped into userspace.
      
      The immediate benefit is that the buffer size can be much bigger, resulting in
      fewer interrupts and no kernel side copying is involved and little to no trace
      data loss. Also, kernel code can be traced with this driver.
      
      The old way of collecting BTS traces still works.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1422614435-114702-1-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      8062382c
    • Alexander Shishkin's avatar
      perf/x86/intel/pt: Add Intel PT PMU driver · 52ca9ced
      Alexander Shishkin authored
      
      
      Add support for Intel Processor Trace (PT) to kernel's perf events.
      PT is an extension of Intel Architecture that collects information about
      software execuction such as control flow, execution modes and timings and
      formats it into highly compressed binary packets. Even being compressed,
      these packets are generated at hundreds of megabytes per second per core,
      which makes it impractical to decode them on the fly in the kernel.
      
      This driver exports trace data by through AUX space in the perf ring
      buffer, which is zero-copy mapped into userspace for faster data retrieval.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1422614392-114498-1-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      52ca9ced
    • Alexander Shishkin's avatar
      perf/x86: Mark Intel PT and LBR/BTS as mutually exclusive · 48070342
      Alexander Shishkin authored
      
      
      Intel PT cannot be used at the same time as LBR or BTS and will cause a
      general protection fault if they are used together. In order to avoid
      fixing up GPs in the fast path, instead we disallow creating LBR/BTS
      events when PT events are present and vice versa.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-12-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      48070342
    • Alexander Shishkin's avatar
      x86: Add Intel Processor Trace (INTEL_PT) cpu feature detection · ed69628b
      Alexander Shishkin authored
      
      
      Intel Processor Trace is an architecture extension that allows for program
      flow tracing.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-11-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      ed69628b
    • Alexander Shishkin's avatar
      perf: Add ITRACE_START record to indicate that tracing has started · ec0d7729
      Alexander Shishkin authored
      
      
      For counters that generate AUX data that is bound to the context of a
      running task, such as instruction tracing, the decoder needs to know
      exactly which task is running when the event is first scheduled in,
      before the first sched_switch. The decoder's need to know this stems
      from the fact that instruction flow trace decoding will almost always
      require program's object code in order to reconstruct said flow and
      for that we need at least its pid/tid in the perf stream.
      
      To single out such instruction tracing pmus, this patch introduces
      ITRACE PMU capability. The reason this is not part of RECORD_AUX
      record is that not all pmus capable of generating AUX data need this,
      and the opposite is *probably* also true.
      
      While sched_switch covers for most cases, there are two problems with it:
      the consumer will need to process events out of order (that is, having
      found RECORD_AUX, it will have to skip forward to the nearest sched_switch
      to figure out which task it was, then go back to the actual trace to
      decode it) and it completely misses the case when the tracing is enabled
      and disabled before sched_switch, for example, via PERF_EVENT_IOC_DISABLE.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-15-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      ec0d7729
    • Alexander Shishkin's avatar
      perf: Add wakeup watermark control to the AUX area · 1a594131
      Alexander Shishkin authored
      
      
      When AUX area gets a certain amount of new data, we want to wake up
      userspace to collect it. This adds a new control to specify how much
      data will cause a wakeup. This is then passed down to pmu drivers via
      output handle's "wakeup" field, so that the driver can find the nearest
      point where it can generate an interrupt.
      
      We repurpose __reserved_2 in the event attribute for this, even though
      it was never checked to be zero before, aux_watermark will only matter
      for new AUX-aware code, so the old code should still be fine.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-10-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      1a594131
    • Alexander Shishkin's avatar
      perf: Support overwrite mode for the AUX area · 2023a0d2
      Alexander Shishkin authored
      
      
      This adds support for overwrite mode in the AUX area, which means "keep
      collecting data till you're stopped", turning AUX area into a circular
      buffer, where new data overwrites old data. It does not depend on data
      buffer's overwrite mode, so that it doesn't lose sideband data that is
      instrumental for processing AUX data.
      
      Overwrite mode is enabled at mapping AUX area read only. Even though
      aux_tail in the buffer's user page might be user writable, it will be
      ignored in this mode.
      
      A PERF_RECORD_AUX with PERF_AUX_FLAG_OVERWRITE set is written to the perf
      data stream every time an event writes new data to the AUX area. The pmu
      driver might not be able to infer the exact beginning of the new data in
      each snapshot, some drivers will only provide the tail, which is
      aux_offset + aux_size in the AUX record. Consumer has to be able to tell
      the new data from the old one, for example, by means of time stamps if
      such are provided in the trace.
      
      Consumer is also responsible for disabling any events that might write
      to the AUX area (thus potentially racing with the consumer) before
      collecting the data.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-9-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      2023a0d2
    • Alexander Shishkin's avatar
      perf: Add API for PMUs to write to the AUX area · fdc26706
      Alexander Shishkin authored
      
      
      For pmus that wish to write data to ring buffer's AUX area, provide
      perf_aux_output_{begin,end}() calls to initiate/commit data writes,
      similarly to perf_output_{begin,end}. These also use the same output
      handle structure. Also, similarly to software counterparts, these
      will direct inherited events' output to parents' ring buffers.
      
      After the perf_aux_output_begin() returns successfully, handle->size
      is set to the maximum amount of data that can be written wrt aux_tail
      pointer, so that no data that the user hasn't seen will be overwritten,
      therefore this should always be called before hardware writing is
      enabled. On success, this will return the pointer to pmu driver's
      private structure allocated for this aux area by pmu::setup_aux. Same
      pointer can also be retrieved using perf_get_aux() while hardware
      writing is enabled.
      
      PMU driver should pass the actual amount of data written as a parameter
      to perf_aux_output_end(). All hardware writes should be completed and
      visible before this one is called.
      
      Additionally, perf_aux_output_skip() will adjust output handle and
      aux_head in case some part of the buffer has to be skipped over to
      maintain hardware's alignment constraints.
      
      Nested writers are forbidden and guards are in place to catch such
      attempts.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-8-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      fdc26706
    • Alexander Shishkin's avatar
      perf: Add AUX record · 68db7e98
      Alexander Shishkin authored
      
      
      When there's new data in the AUX space, output a record indicating its
      offset and size and a set of flags, such as PERF_AUX_FLAG_TRUNCATED, to
      mean the described data was truncated to fit in the ring buffer.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-7-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      68db7e98
    • Alexander Shishkin's avatar
      perf: Add a pmu capability for "exclusive" events · bed5b25a
      Alexander Shishkin authored
      
      
      Usually, pmus that do, for example, instruction tracing, would only ever
      be able to have one event per task per cpu (or per perf_event_context). For
      such pmus it makes sense to disallow creating conflicting events early on,
      so as to provide consistent behavior for the user.
      
      This patch adds a pmu capability that indicates such constraint on event
      creation.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1422613866-113186-1-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      bed5b25a
    • Alexander Shishkin's avatar
      perf: Add a capability for AUX_NO_SG pmus to do software double buffering · 6a279230
      Alexander Shishkin authored
      
      
      For pmus that don't support scatter-gather for AUX data in hardware, it
      might still make sense to implement software double buffering to avoid
      losing data while the user is reading data out. For this purpose, add
      a pmu capability that guarantees multiple high-order chunks for AUX buffer,
      so that the pmu driver can do switchover tricks.
      
      To make use of this feature, add PERF_PMU_CAP_AUX_SW_DOUBLEBUF to your
      pmu's capability mask. This will make the ring buffer AUX allocation code
      ensure that the biggest high order allocation for the aux buffer pages is
      no bigger than half of the total requested buffer size, thus making sure
      that the buffer has at least two high order allocations.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-5-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      6a279230
    • Alexander Shishkin's avatar
      perf: Support high-order allocations for AUX space · 0a4e38e6
      Alexander Shishkin authored
      
      
      Some pmus (such as BTS or Intel PT without multiple-entry ToPA capability)
      don't support scatter-gather and will prefer larger contiguous areas for
      their output regions.
      
      This patch adds a new pmu capability to request higher order allocations.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-4-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      0a4e38e6
    • Peter Zijlstra's avatar
      perf: Add AUX area to ring buffer for raw data streams · 45bfb2e5
      Peter Zijlstra authored
      
      
      This patch introduces "AUX space" in the perf mmap buffer, intended for
      exporting high bandwidth data streams to userspace, such as instruction
      flow traces.
      
      AUX space is a ring buffer, defined by aux_{offset,size} fields in the
      user_page structure, and read/write pointers aux_{head,tail}, which abide
      by the same rules as data_* counterparts of the main perf buffer.
      
      In order to allocate/mmap AUX, userspace needs to set up aux_offset to
      such an offset that will be greater than data_offset+data_size and
      aux_size to be the desired buffer size. Both need to be page aligned.
      Then, same aux_offset and aux_size should be passed to mmap() call and
      if everything adds up, you should have an AUX buffer as a result.
      
      Pages that are mapped into this buffer also come out of user's mlock
      rlimit plus perf_event_mlock_kb allowance.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-3-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      45bfb2e5
    • Alexander Shishkin's avatar
      perf: Add data_{offset,size} to user_page · e8c6deac
      Alexander Shishkin authored
      
      
      Currently, the actual perf ring buffer is one page into the mmap area,
      following the user page and the userspace follows this convention. This
      patch adds data_{offset,size} fields to user_page that can be used by
      userspace instead for locating perf data in the mmap area. This is also
      helpful when mapping existing or shared buffers if their size is not
      known in advance.
      
      Right now, it is made to follow the existing convention that
      
      	data_offset == PAGE_SIZE and
      	data_offset + data_size == mmap_size.
      Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@linux.intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      e8c6deac
    • Andi Kleen's avatar
      perf/x86/intel: Fix Haswell CYCLE_ACTIVITY.* counter constraints · c420f19b
      Andi Kleen authored
      
      
      Some of the CYCLE_ACTIVITY.* events can only be scheduled on
      counter 2.  Due to a typo Haswell matched those with
      INTEL_EVENT_CONSTRAINT, which lead to the events never
      matching as the comparison does not expect anything
      in the umask too. Fix the typo.
      Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1425925222-32361-1-git-send-email-andi@firstfloor.org
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      c420f19b
    • Kan Liang's avatar
      perf/x86/intel: Filter branches for PEBS event · 687805e4
      Kan Liang authored
      For supporting Intel LBR branches filtering, Intel LBR sharing logic
      mechanism is introduced from commit b36817e8
      
       ("perf/x86: Add Intel
      LBR sharing logic"). It modifies __intel_shared_reg_get_constraints() to
      config lbr_sel, which is finally used to set LBR_SELECT.
      
      However, the intel_shared_regs_constraints() function is called after
      intel_pebs_constraints(). The PEBS event will return immediately after
      intel_pebs_constraints(). So it's impossible to filter branches for PEBS
      events.
      
      This patch moves intel_shared_regs_constraints() ahead of
      intel_pebs_constraints().
      
      We can safely do that because the intel_shared_regs_constraints() function
      only returns empty constraint if its rejecting the event, otherwise it
      returns NULL such that we continue calling intel_pebs_constraints() and
      x86_get_event_constraint().
      Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: eranian@google.com
      Link: http://lkml.kernel.org/r/1427467105-9260-1-git-send-email-kan.liang@intel.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      687805e4
    • Ingo Molnar's avatar
      bpf: Fix the build on BPF_SYSCALL=y && !CONFIG_TRACING kernels, make it more configurable · e1abf2cc
      Ingo Molnar authored
      
      
      So bpf_tracing.o depends on CONFIG_BPF_SYSCALL - but that's not its only
      dependency, it also depends on the tracing infrastructure and on kprobes,
      without which it will fail to build with:
      
        In file included from kernel/trace/bpf_trace.c:14:0:
        kernel/trace/trace.h: In function ‘trace_test_and_set_recursion’:
        kernel/trace/trace.h:491:28: error: ‘struct task_struct’ has no member named ‘trace_recursion’
          unsigned int val = current->trace_recursion;
        [...]
      
      It took quite some time to trigger this build failure, because right now
      BPF_SYSCALL is very obscure, depends on CONFIG_EXPERT. So also make BPF_SYSCALL
      more configurable, not just under CONFIG_EXPERT.
      
      If BPF_SYSCALL, tracing and kprobes are enabled then enable the bpf_tracing
      gateway as well.
      
      We might want to make this an interactive option later on, although
      I'd not complicate it unnecessarily: enabling BPF_SYSCALL is enough of
      an indicator that the user wants BPF support.
      
      Cc: Alexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      e1abf2cc
    • Alexei Starovoitov's avatar
      samples/bpf: Add kmem_alloc()/free() tracker tool · 9811e353
      Alexei Starovoitov authored
      
      
      One BPF program attaches to kmem_cache_alloc_node() and
      remembers all allocated objects in the map.
      Another program attaches to kmem_cache_free() and deletes
      corresponding object from the map.
      
      User space walks the map every second and prints any objects
      which are older than 1 second.
      
      Usage:
      
      	$ sudo tracex4
      
      Then start few long living processes. The 'tracex4' will print
      something like this:
      
      	obj 0xffff880465928000 is 13sec old was allocated at ip ffffffff8105dc32
      	obj 0xffff88043181c280 is 13sec old was allocated at ip ffffffff8105dc32
      	obj 0xffff880465848000 is  8sec old was allocated at ip ffffffff8105dc32
      	obj 0xffff8804338bc280 is 15sec old was allocated at ip ffffffff8105dc32
      
      	$ addr2line -fispe vmlinux ffffffff8105dc32
      	do_fork at fork.c:1665
      
      As soon as processes exit the memory is reclaimed and 'tracex4'
      prints nothing.
      
      Similar experiment can be done with the __kmalloc()/kfree() pair.
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-10-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      9811e353
    • Alexei Starovoitov's avatar
      samples/bpf: Add IO latency analysis (iosnoop/heatmap) tool · 5c7fc2d2
      Alexei Starovoitov authored
      
      
      BPF C program attaches to
      blk_mq_start_request()/blk_update_request() kprobe events to
      calculate IO latency.
      
      For every completed block IO event it computes the time delta
      in nsec and records in a histogram map:
      
      	map[log10(delta)*10]++
      
      User space reads this histogram map every 2 seconds and prints
      it as a 'heatmap' using gray shades of text terminal. Black
      spaces have many events and white spaces have very few events.
      Left most space is the smallest latency, right most space is
      the largest latency in the range.
      
      Usage:
      
      	$ sudo ./tracex3
      	and do 'sudo dd if=/dev/sda of=/dev/null' in other terminal.
      
      Observe IO latencies and how different activity (like 'make
      kernel') affects it.
      
      Similar experiments can be done for network transmit latencies,
      syscalls, etc.
      
      '-t' flag prints the heatmap using normal ascii characters:
      
      $ sudo ./tracex3 -t
        heatmap of IO latency
        # - many events with this latency
          - few events
      	|1us      |10us     |100us    |1ms      |10ms     |100ms    |1s |10s
      				 *ooo. *O.#.                                    # 221
      			      .  *#     .                                       # 125
      				 ..   .o#*..                                    # 55
      			    .  . .  .  .#O                                      # 37
      				 .#                                             # 175
      				       .#*.                                     # 37
      				  #                                             # 199
      		      .              . *#*.                                     # 55
      				       *#..*                                    # 42
      				  #                                             # 266
      			      ...***Oo#*OO**o#* .                               # 629
      				  #                                             # 271
      				      . .#o* o.*o*                              # 221
      				. . o* *#O..                                    # 50
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-9-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      5c7fc2d2
    • Alexei Starovoitov's avatar
      samples/bpf: Add counting example for kfree_skb() function calls and the write() syscall · d822a192
      Alexei Starovoitov authored
      
      
      this example has two probes in one C file that attach to
      different kprove events and use two different maps.
      
      1st probe is x64 specific equivalent of dropmon. It attaches to
      kfree_skb, retrevies 'ip' address of kfree_skb() caller and
      counts number of packet drops at that 'ip' address. User space
      prints 'location - count' map every second.
      
      2nd probe attaches to kprobe:sys_write and computes a histogram
      of different write sizes
      
      Usage:
      	$ sudo tracex2
      	location 0xffffffff81695995 count 1
      	location 0xffffffff816d0da9 count 2
      
      	location 0xffffffff81695995 count 2
      	location 0xffffffff816d0da9 count 2
      
      	location 0xffffffff81695995 count 3
      	location 0xffffffff816d0da9 count 2
      
      	557145+0 records in
      	557145+0 records out
      	285258240 bytes (285 MB) copied, 1.02379 s, 279 MB/s
      		   syscall write() stats
      	     byte_size       : count     distribution
      	       1 -> 1        : 3        |                                      |
      	       2 -> 3        : 0        |                                      |
      	       4 -> 7        : 0        |                                      |
      	       8 -> 15       : 0        |                                      |
      	      16 -> 31       : 2        |                                      |
      	      32 -> 63       : 3        |                                      |
      	      64 -> 127      : 1        |                                      |
      	     128 -> 255      : 1        |                                      |
      	     256 -> 511      : 0        |                                      |
      	     512 -> 1023     : 1118968  |************************************* |
      
      Ctrl-C at any time. Kernel will auto cleanup maps and programs
      
      	$ addr2line -ape ./bld_x64/vmlinux 0xffffffff81695995
      	0xffffffff816d0da9 0xffffffff81695995:
      	./bld_x64/../net/ipv4/icmp.c:1038 0xffffffff816d0da9:
      	./bld_x64/../net/unix/af_unix.c:1231
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-8-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      d822a192
    • Alexei Starovoitov's avatar
      samples/bpf: Add simple non-portable kprobe filter example · b896c4f9
      Alexei Starovoitov authored
      
      
      tracex1_kern.c - C program compiled into BPF.
      
      It attaches to kprobe:netif_receive_skb()
      
      When skb->dev->name == "lo", it prints sample debug message into
      trace_pipe via bpf_trace_printk() helper function.
      
      tracex1_user.c - corresponding user space component that:
        - loads BPF program via bpf() syscall
        - opens kprobes:netif_receive_skb event via perf_event_open()
          syscall
        - attaches the program to event via ioctl(event_fd,
          PERF_EVENT_IOC_SET_BPF, prog_fd);
        - prints from trace_pipe
      
      Note, this BPF program is non-portable. It must be recompiled
      with current kernel headers. kprobe is not a stable ABI and
      BPF+kprobe scripts may no longer be meaningful when kernel
      internals change.
      
      No matter in what way the kernel changes, neither the kprobe,
      nor the BPF program can ever crash or corrupt the kernel,
      assuming the kprobes, perf and BPF subsystem has no bugs.
      
      The verifier will detect that the program is using
      bpf_trace_printk() and the kernel will print 'this is a DEBUG
      kernel' warning banner, which means that bpf_trace_printk()
      should be used for debugging of the BPF program only.
      
      Usage:
      $ sudo tracex1
                  ping-19826 [000] d.s2 63103.382648: : skb ffff880466b1ca00 len 84
                  ping-19826 [000] d.s2 63103.382684: : skb ffff880466b1d300 len 84
      
                  ping-19826 [000] d.s2 63104.382533: : skb ffff880466b1ca00 len 84
                  ping-19826 [000] d.s2 63104.382594: : skb ffff880466b1d300 len 84
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-7-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      b896c4f9
    • Alexei Starovoitov's avatar
      tracing: Allow BPF programs to call bpf_trace_printk() · 9c959c86
      Alexei Starovoitov authored
      
      
      Debugging of BPF programs needs some form of printk from the
      program, so let programs call limited trace_printk() with %d %u
      %x %p modifiers only.
      
      Similar to kernel modules, during program load verifier checks
      whether program is calling bpf_trace_printk() and if so, kernel
      allocates trace_printk buffers and emits big 'this is debug
      only' banner.
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-6-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      9c959c86
    • Alexei Starovoitov's avatar
      tracing: Allow BPF programs to call bpf_ktime_get_ns() · d9847d31
      Alexei Starovoitov authored
      
      
      bpf_ktime_get_ns() is used by programs to compute time delta
      between events or as a timestamp
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-5-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      d9847d31
    • Alexei Starovoitov's avatar
      tracing, perf: Implement BPF programs attached to kprobes · 2541517c
      Alexei Starovoitov authored
      
      
      BPF programs, attached to kprobes, provide a safe way to execute
      user-defined BPF byte-code programs without being able to crash or
      hang the kernel in any way. The BPF engine makes sure that such
      programs have a finite execution time and that they cannot break
      out of their sandbox.
      
      The user interface is to attach to a kprobe via the perf syscall:
      
      	struct perf_event_attr attr = {
      		.type	= PERF_TYPE_TRACEPOINT,
      		.config	= event_id,
      		...
      	};
      
      	event_fd = perf_event_open(&attr,...);
      	ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
      
      'prog_fd' is a file descriptor associated with BPF program
      previously loaded.
      
      'event_id' is an ID of the kprobe created.
      
      Closing 'event_fd':
      
      	close(event_fd);
      
      ... automatically detaches BPF program from it.
      
      BPF programs can call in-kernel helper functions to:
      
        - lookup/update/delete elements in maps
      
        - probe_read - wraper of probe_kernel_read() used to access any
          kernel data structures
      
      BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
      architecture dependent) and return 0 to ignore the event and 1 to store
      kprobe event into the ring buffer.
      
      Note, kprobes are a fundamentally _not_ a stable kernel ABI,
      so BPF programs attached to kprobes must be recompiled for
      every kernel version and user must supply correct LINUX_VERSION_CODE
      in attr.kern_version during bpf_prog_load() call.
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Reviewed-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      2541517c
    • Alexei Starovoitov's avatar
      tracing: Add kprobe flag · 72cbbc89
      Alexei Starovoitov authored
      
      
      add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of
      tracepoints, since bpf programs can only be attached to kprobe
      type of PERF_TYPE_TRACEPOINT perf events.
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Reviewed-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-3-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      72cbbc89
    • Daniel Borkmann's avatar
      bpf: Make internal bpf API independent of CONFIG_BPF_SYSCALL #ifdefs · 4e537f7f
      Daniel Borkmann authored
      
      
      Socket filter code and other subsystems with upcoming eBPF
      support should not need to deal with the fact that we have
      CONFIG_BPF_SYSCALL defined or not.
      
      Having the bpf syscall as a config option is a nice thing and
      I'd expect it to stay that way for expert users (I presume one
      day the default setting of it might change, though), but code
      making use of it should not care if it's actually enabled or
      not.
      
      Instead, hide this via header files and let the rest deal with it.
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-2-git-send-email-ast@plumgrid.com
      
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      4e537f7f
    • Ingo Molnar's avatar
      Merge branch 'perf/timer' into perf/core · 223aa646
      Ingo Molnar authored
      
      
      This WIP branch is now ready to be merged.
      Signed-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
      223aa646
  2. 01 Apr, 2015 1 commit
  3. 31 Mar, 2015 5 commits
  4. 30 Mar, 2015 1 commit
  5. 29 Mar, 2015 1 commit