kernel/linux.git/tools/perf/util/session.c, branch v3.18.4

perf session: Do not fail on processing out of order event

2015-01-16T14:59:56+00:00

commit f61ff6c06dc8f32c7036013ad802c899ec590607 upstream. Linus reported perf report command being interrupted due to processing of 'out of order' event, with following error: Timestamp below last timeslice flush 0x5733a8 [0x28]: failed to process type: 3 I could reproduce the issue and in my case it was caused by one CPU (mmap) being behind during record and userspace mmap reader seeing the data after other CPUs data were already stored. This is expected under some circumstances because we need to limit the number of events that we queue for reordering when we receive a PERF_RECORD_FINISHED_ROUND or when we force flush due to memory pressure. Reported-by: Linus Torvalds Signed-off-by: Jiri Olsa Acked-by: Ingo Molnar Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Linus Torvalds Cc: Matt Fleming Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1417016371-30249-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Zhiqiang Zhang Signed-off-by: Greg Kroah-Hartman

perf session: Add option to copy events when queueing

2014-10-15T20:39:03+00:00

When processing events the session code has an ordered samples queue which is used to time-sort events coming in across multiple mmaps. At a later point in time samples on the queue are flushed up to some timestamp at which point the event is actually processed. When analyzing events live (ie., record/analysis path in the same command) there is a race that leads to corrupted events and parse errors which cause perf to terminate. The problem is that when the event is placed in the ordered samples queue it is only a reference to the event which is really sitting in the mmap buffer. Even though the event is queued for later processing the mmap tail pointer is updated which indicates to the kernel that the event has been processed. The race is flushing the event from the queue before it gets overwritten by some other event. For commands trying to process events live (versus just writing to a file) and processing a high rate of events this leads to parse failures and perf terminates. Examples hitting this problem are 'perf kvm stat live', especially with nested VMs which generate 100,000+ traces per second, and a command processing scheduling events with a high rate of context switching -- e.g., running 'perf bench sched pipe'. This patch offers live commands an option to copy the event when it is placed in the ordered samples queue. Based on a patch from David Ahern Signed-off-by: Alexander Yarygin Acked-by: Jiri Olsa Cc: Christian Borntraeger Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1412347212-28237-2-git-send-email-yarygin@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf session: Remove last reference to hists struct

2014-10-14T14:41:25+00:00

Now perf_session doesn't require that the evsels in its evlist are hists containing ones. Tools that are hists based and want to do per evsel events_stats updates, if at some point this turns into a necessity, should do it in the tool specific code, keeping the session class hists agnostic. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jean Pihet Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-cli1bgwpo82mdikuhy3djsuy@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf session: Don't count per evsel events

2014-10-10T18:15:32+00:00

PERF_RECORD_SAMPLE was not being counted here and is the only per-evsel thing anyway, the other events were not mapping to a evsel. With this we don't require that evsels used with a perf_session need to have space for hists, like the ones in annotate, report, top. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jean Pihet Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-kzchpz0l1mhrsfpkirz086m2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Add hists helper

2014-10-09T16:13:41+00:00

Not all tools need a hists instance per perf_evsel, so lets pave the way to remove evsel->hists while leaving a way to access the hists from a specially allocated evsel, one that comes with space at the end where lives the evsel. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jean Pihet Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-qlktkhe31w4mgtbd84035sr2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix perf record as non root with kptr_restrict == 1

2014-09-26T13:51:41+00:00

Currently perf record always errors out when you run it as non-root with kptr_restrict == 1, which is often the default. Make it only warn instead and fix the kernel resolve code to not segfault later. Profiling works still fine, except kernel symbols are not resolved. Signed-off-by: Andi Kleen Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1411594794-7229-1-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Add machine__thread_exec_comm()

2014-08-13T22:23:21+00:00

Add machine__thread_exec_comm() to return the comm that matches the last exec, if the comm_exec flag is present, or the last comm otherwise. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1406786474-9306-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf session: Add perf_session__peek_event()

2014-08-13T22:21:44+00:00

Add a function to peek at other events in the event stream. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1406786474-9306-15-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow out of order messages in forced flush

2014-08-12T15:03:02+00:00

In forced flush (OE_FLUSH__HALF) we break the rules of the flush timestamp via PERF_RECORD_FINISHED_ROUND event, so we could get out of order event. Do not force error in this case plus changing the output warning to use WARN_ONCE. Signed-off-by: Jiri Olsa Acked-by: David Ahern Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jean Pihet Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-8q8794a8nlmpd1u8xrqmcyd2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add debug prints for ordered events queue

2014-08-12T15:03:01+00:00

Adding some prints for ordered events queue, to help debug issues. Adding debug_ordered_events debug variable to be able to enable ordered events debug messages using: $ perf --debug ordered-events=2 report ... Also using oe pointer in perf_session__queue_event instead of chained session variable dereferencing. Signed-off-by: Jiri Olsa Acked-by: David Ahern Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jean Pihet Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-7p3mnnopjvsp9nmk9msqcfkm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo