From: "tip-bot2 for Kan Liang" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Kan Liang <kan.liang@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Alexey Budankov <alexey.budankov@linux.intel.com>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Namhyung Kim <namhyung@kernel.org>,
Pavel Gerasimov <pavel.gerasimov@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
Stephane Eranian <eranian@google.com>,
Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>,
x86 <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: [tip: perf/core] perf report: Add option to enable the LBR stitching approach
Date: Wed, 22 Apr 2020 12:17:11 -0000 [thread overview]
Message-ID: <158755783149.28353.15798067908871951560.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200319202517.23423-14-kan.liang@linux.intel.com>
The following commit has been merged into the perf/core branch of tip:
Commit-ID: b1d1429b1820e1587d8588fc05b28ef9af42cfc6
Gitweb: https://git.kernel.org/tip/b1d1429b1820e1587d8588fc05b28ef9af42cfc6
Author: Kan Liang <kan.liang@linux.intel.com>
AuthorDate: Thu, 19 Mar 2020 13:25:13 -07:00
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Sat, 18 Apr 2020 09:05:01 -03:00
perf report: Add option to enable the LBR stitching approach
With the LBR stitching approach, the reconstructed LBR call stack can
break the HW limitation. However, it may reconstruct invalid call stacks
in some cases, e.g. exception handing such as setjmp/longjmp. Also, it
may impact the processing time especially when the number of samples
with stitched LBRs are huge.
Add an option to enable the approach.
# To display the perf.data header info, please use
# --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles'
# Event count (approx.): 6492797701
#
# Children Self Command Shared Object Symbol
# ........ ........ ............... ..................
# .................................
#
99.99% 99.99% tchain_edit tchain_edit [.] f43
|
---main
f1
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f31
|
--99.65%--f32
f33
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f42
f43
Committer testing:
$ perf record --call-graph lbr /wb/tchain_edit
[ perf record: Woken up 23 times to write data ]
[ perf record: Captured and wrote 5.578 MB perf.data (6839 samples) ]
$ perf report --header-only | egrep 'cpu(desc|.*capabilities)'
# cpudesc : Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz
# cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
$
Before:
$ perf report --no-children --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles:u'
# Event count (approx.): 6459523879
#
# Overhead Command Shared Object Symbol
# ........ ........... ................ .......................
#
99.95% tchain_edit tchain_edit [.] f43
|
--99.92%--f43
f42
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0.03% tchain_edit tchain_edit [.] f42
0.01% tchain_edit tchain_edit [.] f41
0.00% tchain_edit tchain_edit [.] f31
0.00% tchain_edit ld-2.29.so [.] _dl_relocate_object
0.00% tchain_edit ld-2.29.so [.] memmove
0.00% tchain_edit [unknown] [k] 0xffffffff93a00b17
After:
$ perf report --stitch-lbr --no-children --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles:u'
# Event count (approx.): 6459496645
#
# Overhead Command Shared Object Symbol
# ........ ........... ................ ........................
#
99.97% tchain_edit tchain_edit [.] f43
|
--99.93%--f43
f42
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f1
main
__libc_start_main
0.02% tchain_edit [unknown] [k] 0xffffffff93a00b17
0.01% tchain_edit tchain_edit [.] f31
0.00% tchain_edit ld-2.29.so [.] _dl_important_hwcaps
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-14-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/Documentation/perf-report.txt | 11 +++++++++++
tools/perf/builtin-report.c | 12 ++++++++++++
2 files changed, 23 insertions(+)
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index f569b9e..d068103 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -488,6 +488,17 @@ include::itrace.txt[]
This option extends the perf report to show reference callgraphs,
which collected by reference event, in no callgraph event.
+--stitch-lbr::
+ Show callgraph with stitched LBRs, which may have more complete
+ callgraph. The perf.data file must have been obtained using
+ perf record --call-graph lbr.
+ Disabled by default. In common cases with call stack overflows,
+ it can recreate better call stacks than the default lbr call stack
+ output. But this approach is not full proof. There can be cases
+ where it creates incorrect call stacks from incorrect matches.
+ The known limitations include exception handing such as
+ setjmp/longjmp will have calls/returns not match.
+
--socket-filter::
Only report the samples on the processor socket that match with this filter
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index c0cebd5..0c32767 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -84,6 +84,7 @@ struct report {
bool header_only;
bool nonany_branch_mode;
bool group_set;
+ bool stitch_lbr;
int max_stack;
struct perf_read_values show_threads_values;
struct annotation_options annotation_opts;
@@ -267,6 +268,9 @@ static int process_sample_event(struct perf_tool *tool,
return -1;
}
+ if (rep->stitch_lbr)
+ al.thread->lbr_stitch_enable = true;
+
if (symbol_conf.hide_unresolved && al.sym == NULL)
goto out_put;
@@ -408,6 +412,12 @@ static int report__setup_sample_type(struct report *rep)
callchain_param.record_mode = CALLCHAIN_FP;
}
+ if (rep->stitch_lbr && (callchain_param.record_mode != CALLCHAIN_LBR)) {
+ ui__warning("Can't find LBR callchain. Switch off --stitch-lbr.\n"
+ "Please apply --call-graph lbr when recording.\n");
+ rep->stitch_lbr = false;
+ }
+
/* ??? handle more cases than just ANY? */
if (!(perf_evlist__combined_branch_type(session->evlist) &
PERF_SAMPLE_BRANCH_ANY))
@@ -1258,6 +1268,8 @@ int cmd_report(int argc, const char **argv)
"Show full source file name path for source lines"),
OPT_BOOLEAN(0, "show-ref-call-graph", &symbol_conf.show_ref_callgraph,
"Show callgraph from reference event"),
+ OPT_BOOLEAN(0, "stitch-lbr", &report.stitch_lbr,
+ "Enable LBR callgraph stitching approach"),
OPT_INTEGER(0, "socket-filter", &report.socket_filter,
"only show processor socket that match with this filter"),
OPT_BOOLEAN(0, "raw-trace", &symbol_conf.raw_trace,
next prev parent reply other threads:[~2020-04-22 12:22 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 20:25 [PATCH V4 00/17] Stitch LBR call stack (Perf Tools) kan.liang
2020-03-19 20:25 ` [PATCH V4 01/17] perf pmu: Add support for PMU capabilities kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 02/17] perf header: Support CPU " kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 03/17] perf record: Clear HEADER_CPU_PMU_CAPS for non LBR call stack mode kan.liang
2020-04-17 14:42 ` Arnaldo Carvalho de Melo
2020-03-19 20:25 ` [PATCH V4 04/17] perf stat: Clear HEADER_CPU_PMU_CAPS kan.liang
2020-04-17 14:42 ` Arnaldo Carvalho de Melo
2020-03-19 20:25 ` [PATCH V4 05/17] perf machine: Remove the indent in resolve_lbr_callchain_sample kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 06/17] perf machine: Refine the function for LBR call stack reconstruction kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 07/17] perf machine: Factor out lbr_callchain_add_kernel_ip() kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 08/17] perf machine: Factor out lbr_callchain_add_lbr_ip() kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 09/17] perf thread: Add a knob for LBR stitch approach kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 10/17] perf tools: Save previous sample for LBR stitching approach kan.liang
2020-04-17 15:02 ` Arnaldo Carvalho de Melo
2020-04-22 12:17 ` [tip: perf/core] perf thread: " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 11/17] perf tools: Save previous cursor nodes " kan.liang
2020-04-17 16:53 ` Arnaldo Carvalho de Melo
2020-04-22 12:17 ` [tip: perf/core] perf callchain: " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 12/17] perf tools: Stitch LBR call stack kan.liang
2020-04-22 12:17 ` [tip: perf/core] perf callchain: " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 13/17] perf report: Add option to enable the LBR stitching approach kan.liang
2020-04-22 12:17 ` tip-bot2 for Kan Liang [this message]
2020-03-19 20:25 ` [PATCH V4 14/17] perf script: " kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 15/17] perf top: " kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 16/17] perf c2c: " kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-19 20:25 ` [PATCH V4 17/17] perf hist: Add fast path for duplicate entries check kan.liang
2020-04-22 12:17 ` [tip: perf/core] " tip-bot2 for Kan Liang
2020-03-23 11:13 ` [PATCH V4 00/17] Stitch LBR call stack (Perf Tools) Jiri Olsa
2020-04-02 15:34 ` Liang, Kan
2020-04-02 16:00 ` Arnaldo Carvalho de Melo
2020-04-02 17:02 ` Liang, Kan
2020-04-17 17:48 ` Arnaldo Carvalho de Melo
2020-04-17 21:47 ` Liang, Kan
2020-04-17 21:54 ` Arnaldo Carvalho de Melo
2020-04-17 21:55 ` Arnaldo Carvalho de Melo
2020-04-17 21:55 ` Arnaldo Carvalho de Melo
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