From: Jin Yao Date: Fri, 8 Dec 2017 13:13:42 +0000 (+0800) Subject: perf record: Record the first and last sample time in the header X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=68588baf8d01826673f2874f434123029e519052;p=openwrt%2Fstaging%2Fblogic.git perf record: Record the first and last sample time in the header In the default 'perf record' configuration, all samples are processed, to create the HEADER_BUILD_ID table. So it's very easy to get the first/last samples and save the time to perf file header via the function write_sample_time(). Later, at post processing time, perf report/script will fetch the time from perf file header. Committer testing: # perf record -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.099 MB perf.data (1101 samples) ] [root@jouet home]# perf report --header | grep "time of " # time of first sample : 22947.909226 # time of last sample : 22948.910704 # # perf report -D | grep PERF_RECORD_SAMPLE\( 0 22947909226101 0x20bb68 [0x30]: PERF_RECORD_SAMPLE(IP, 0x4001): 0/0: 0xffffffffa21b1af3 period: 1 addr: 0 0 22947909229928 0x20bb98 [0x30]: PERF_RECORD_SAMPLE(IP, 0x4001): 0/0: 0xffffffffa200d204 period: 1 addr: 0 3 22948910397351 0x219360 [0x30]: PERF_RECORD_SAMPLE(IP, 0x4001): 28251/28251: 0xffffffffa22071d8 period: 169518 addr: 0 0 22948910652380 0x20f120 [0x30]: PERF_RECORD_SAMPLE(IP, 0x4001): 0/0: 0xffffffffa2856816 period: 198807 addr: 0 2 22948910704034 0x2172d0 [0x30]: PERF_RECORD_SAMPLE(IP, 0x4001): 0/0: 0xffffffffa2856816 period: 88111 addr: 0 # Changelog: v7: Just update the patch description according to Arnaldo's suggestion. v6: Currently '--buildid-all' is not enabled at default. So the walking on all samples is the default operation. There is no big overhead to calculate the timestamp boundary in process_sample_event handler once we already go through all samples. So the timestamp boundary calculation is enabled by default when '--buildid-all' is not enabled. While if '--buildid-all' is enabled, we creates a new option "--timestamp-boundary" for user to decide if it enables the timestamp boundary calculation. v5: There is an issue that the sample walking can only work when '--buildid-all' is not enabled. So we need to let the walking be able to work even if '--buildid-all' is enabled and let the processing skips the dso hit marking for this case. At first, I want to provide a new option "--record-time-boundaries". While after consideration, I think a new option is not very necessary. v3: Remove the definitions of first_sample_time and last_sample_time from struct record and directly save them in perf_evlist. Signed-off-by: Jin Yao Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andi Kleen Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1512738826-2628-3-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 5a626ef666c2..3eea6de35a38 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -430,6 +430,9 @@ Configure all used events to run in user space. --timestamp-filename Append timestamp to output file name. +--timestamp-boundary:: +Record timestamp boundary (time of first/last samples). + --switch-output[=mode]:: Generate multiple perf.data files, timestamp prefixed, switching to a new one based on 'mode' value: diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 50385d89c497..65681a1a292a 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -78,6 +78,7 @@ struct record { bool no_buildid_cache_set; bool buildid_all; bool timestamp_filename; + bool timestamp_boundary; struct switch_output switch_output; unsigned long long samples; }; @@ -409,8 +410,15 @@ static int process_sample_event(struct perf_tool *tool, { struct record *rec = container_of(tool, struct record, tool); - rec->samples++; + if (rec->evlist->first_sample_time == 0) + rec->evlist->first_sample_time = sample->time; + + rec->evlist->last_sample_time = sample->time; + if (rec->buildid_all) + return 0; + + rec->samples++; return build_id__mark_dso_hit(tool, event, sample, evsel, machine); } @@ -435,9 +443,11 @@ static int process_buildids(struct record *rec) /* * If --buildid-all is given, it marks all DSO regardless of hits, - * so no need to process samples. + * so no need to process samples. But if timestamp_boundary is enabled, + * it still needs to walk on all samples to get the timestamps of + * first/last samples. */ - if (rec->buildid_all) + if (rec->buildid_all && !rec->timestamp_boundary) rec->tool.sample = NULL; return perf_session__process_events(session); @@ -1621,6 +1631,8 @@ static struct option __record_options[] = { "Record build-id of all DSOs regardless of hits"), OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename, "append timestamp to output filename"), + OPT_BOOLEAN(0, "timestamp-boundary", &record.timestamp_boundary, + "Record timestamp boundary (time of first/last samples)"), OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str, &record.switch_output.set, "signal,size,time", "Switch output when receive SIGUSR2 or cross size,time threshold",