Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Alexander Shishkin <> | Subject | Re: [PATCH 0/4] perf, pt, coresight: AUX flags and VMX update | Date | Mon, 20 Feb 2017 17:18:12 +0200 |
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Alexander Shishkin <alexander.shishkin@linux.intel.com> writes:
> With the vmm_exclusive=0, PT seems to be much more usable on BDW now. This > patchset does three things: > * adds a flag to PERF_RECORD_AUX, signalling that a transaction has gaps > in it (due to VMX root mode kicking in),
Hi Arnaldo & Adrian,
In the above context, will something like this be fine?
Regards, -- Alex
From 5aba03e79c1119408b44435af8c4cee2480b0775 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin <alexander.shishkin@linux.intel.com> Date: Mon, 20 Feb 2017 17:08:53 +0200 Subject: [PATCH] perf tools: Handle partial AUX records and print a warning
This patch decodes the 'partial' flag in AUX records and prints a warning to the user, so that they don't have to guess why their PT traces contain gaps (or missing altogether):
> Warning: > AUX data had gaps in it 6 times out of 8! > > Are you running a KVM guest in the background?
Currently this is the only reason for partial records.
Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> --- tools/include/uapi/linux/perf_event.h | 1 + tools/perf/util/event.c | 5 +++-- tools/perf/util/event.h | 1 + tools/perf/util/session.c | 17 ++++++++++++++--- 4 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index c66a485a24..8306415207 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -885,6 +885,7 @@ enum perf_callchain_context { */ #define PERF_AUX_FLAG_TRUNCATED 0x01 /* record was truncated to fit */ #define PERF_AUX_FLAG_OVERWRITE 0x02 /* snapshot from overwrite mode */ +#define PERF_AUX_FLAG_PARTIAL 0x04 /* record contains gaps */ #define PERF_FLAG_FD_NO_GROUP (1UL << 0) #define PERF_FLAG_FD_OUTPUT (1UL << 1) diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 4ea7ce72ed..ba193cd019 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -1153,11 +1153,12 @@ int perf_event__process_exit(struct perf_tool *tool __maybe_unused, size_t perf_event__fprintf_aux(union perf_event *event, FILE *fp) { - return fprintf(fp, " offset: %#"PRIx64" size: %#"PRIx64" flags: %#"PRIx64" [%s%s]\n", + return fprintf(fp, " offset: %#"PRIx64" size: %#"PRIx64" flags: %#"PRIx64" [%s%s%s]\n", event->aux.aux_offset, event->aux.aux_size, event->aux.flags, event->aux.flags & PERF_AUX_FLAG_TRUNCATED ? "T" : "", - event->aux.flags & PERF_AUX_FLAG_OVERWRITE ? "O" : ""); + event->aux.flags & PERF_AUX_FLAG_OVERWRITE ? "O" : "", + event->aux.flags & PERF_AUX_FLAG_PARTIAL ? "P" : ""); } size_t perf_event__fprintf_itrace_start(union perf_event *event, FILE *fp) diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h index c735c53a26..d7e53fe176 100644 --- a/tools/perf/util/event.h +++ b/tools/perf/util/event.h @@ -269,6 +269,7 @@ struct events_stats { u64 total_lost; u64 total_lost_samples; u64 total_aux_lost; + u64 total_aux_partial; u64 total_invalid_chains; u32 nr_events[PERF_RECORD_HEADER_MAX]; u32 nr_non_filtered_samples; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 4cdbc8f5f1..abdb797fa4 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1258,9 +1258,12 @@ static int machines__deliver_event(struct machines *machines, case PERF_RECORD_UNTHROTTLE: return tool->unthrottle(tool, event, sample, machine); case PERF_RECORD_AUX: - if (tool->aux == perf_event__process_aux && - (event->aux.flags & PERF_AUX_FLAG_TRUNCATED)) - evlist->stats.total_aux_lost += 1; + if (tool->aux == perf_event__process_aux) { + if (event->aux.flags & PERF_AUX_FLAG_TRUNCATED) + evlist->stats.total_aux_lost += 1; + if (event->aux.flags & PERF_AUX_FLAG_PARTIAL) + evlist->stats.total_aux_partial += 1; + } return tool->aux(tool, event, sample, machine); case PERF_RECORD_ITRACE_START: return tool->itrace_start(tool, event, sample, machine); @@ -1548,6 +1551,14 @@ static void perf_session__warn_about_errors(const struct perf_session *session) stats->nr_events[PERF_RECORD_AUX]); } + if (session->tool->aux == perf_event__process_aux && + stats->total_aux_partial != 0) { + ui__warning("AUX data had gaps in it %" PRIu64 " times out of %u!\n\n" + "Are you running a KVM guest in the background?\n\n", + stats->total_aux_partial, + stats->nr_events[PERF_RECORD_AUX]); + } + if (stats->nr_unknown_events != 0) { ui__warning("Found %u unknown events!\n\n" "Is this an older tool processing a perf.data " -- 2.11.0
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