Post processing at perf record takes long time on big machines. What it
does is to find build-id of related binaries. Sometimes we just want to
skip the processing and get the result quickly. Add a new config option
to control this behavior.
The record.build-id config variable can have one of following:
- cache: post-process data and save/update the binaries into the
build-id cache (in ~/.debug). This is default.
- no-cache: post-process data but not update the build-id cache.
Same effect with using -N option.
- skip: skip post-processing and not update the cache.
Same effect with using -B option.
Reported-by: Peter Zijlstra <pet...@infradead.org>
Cc: Taeung Song <treeze.tae...@gmail.com>
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/Documentation/perf-record.txt | 11 ++++++++++-
tools/perf/builtin-record.c | 13 +++++++++++++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/tools/perf/Documentation/perf-record.txt
b/tools/perf/Documentation/perf-record.txt
index e630a7d2c348..809ac8701808 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -207,11 +207,20 @@ comma-separated list with no space: 0,1. Ranges of CPUs
are specified with -: 0-
In per-thread mode with inheritance mode on (default), samples are captured
only when
the thread executes on the designated CPUs. Default is to monitor all CPUs.
+-B::
+--no-buildid::
+Do not save the buildid of (used) binaries in the data file. This skips
+post-processing after recoring which might take some time on big machines.
+The Downside is that it can resolve into a wrong symbol after a binary is
+rebuilt later. You can also set "record.build-id" config variable to
+'skip' to have same effect.
+
-N::
--no-buildid-cache::
Do not update the buildid cache. This saves some overhead in situations
where the information in the perf.data file (which includes buildids)
-is sufficient.
+is sufficient. You can also set "record.build-id" config variable to
+'no-cache' to have same effect.
-G name,...::
--cgroup name,...::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 199fc31e3919..424de323c1f8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -837,6 +837,19 @@ int record_callchain_opt(const struct option *opt,
static int perf_record_config(const char *var, const char *value, void *cb)
{
+ struct record *rec = cb;
+
+ if (!strcmp(var, "record.build-id")) {
+ if (!strcmp(value, "cache"))
+ rec->no_buildid_cache = false;
+ else if (!strcmp(value, "no-cache"))
+ rec->no_buildid_cache = true;
+ else if (!strcmp(value, "skip"))
+ rec->no_buildid = true;
+ else
+ return -1;
+ return 0;
+ }
if (!strcmp(var, "record.call-graph"))
var = "call-graph.record-mode"; /* fall-through */
--
2.6.4
--
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