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Diffstat (limited to 'tools/perf/Documentation/perf-timechart.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-timechart.txt | 79 |
1 files changed, 56 insertions, 23 deletions
diff --git a/tools/perf/Documentation/perf-timechart.txt b/tools/perf/Documentation/perf-timechart.txt index bc5990c33dc..df98d1c8268 100644 --- a/tools/perf/Documentation/perf-timechart.txt +++ b/tools/perf/Documentation/perf-timechart.txt @@ -15,10 +15,20 @@ DESCRIPTION There are two variants of perf timechart: 'perf timechart record <command>' to record the system level events - of an arbitrary workload. + of an arbitrary workload. By default timechart records only scheduler + and CPU events (task switches, running times, CPU power states, etc), + but it's possible to record IO (disk, network) activity using -I argument. 'perf timechart' to turn a trace into a Scalable Vector Graphics file, - that can be viewed with popular SVG viewers such as 'Inkscape'. + that can be viewed with popular SVG viewers such as 'Inkscape'. Depending + on the events in the perf.data file, timechart will contain scheduler/cpu + events or IO events. + + In IO mode, every bar has two charts: upper and lower. + Upper bar shows incoming events (disk reads, ingress network packets). + Lower bar shows outgoing events (disk writes, egress network packets). + There are also poll bars which show how much time application spent + in poll/epoll/select syscalls. TIMECHART OPTIONS ----------------- @@ -43,27 +53,6 @@ TIMECHART OPTIONS --symfs=<directory>:: Look for files with symbols relative to this directory. - -EXAMPLES --------- - -$ perf timechart record git pull - - [ perf record: Woken up 13 times to write data ] - [ perf record: Captured and wrote 4.253 MB perf.data (~185801 samples) ] - -$ perf timechart - - Written 10.2 seconds of trace to output.svg. - -Record system-wide timechart: - - $ perf timechart record - - then generate timechart and highlight 'gcc' tasks: - - $ perf timechart --highlight gcc - -n:: --proc-num:: Print task info for at least given number of tasks. @@ -75,6 +64,19 @@ Record system-wide timechart: duration or tasks with given name. If number is given it's interpreted as number of nanoseconds. If non-numeric string is given it's interpreted as task name. +--io-skip-eagain:: + Don't draw EAGAIN IO events. +--io-min-time=<nsecs>:: + Draw small events as if they lasted min-time. Useful when you need + to see very small and fast IO. It's possible to specify ms or us + suffix to specify time in milliseconds or microseconds. + Default value is 1ms. +--io-merge-dist=<nsecs>:: + Merge events that are merge-dist nanoseconds apart. + Reduces number of figures on the SVG and makes it more render-friendly. + It's possible to specify ms or us suffix to specify time in + milliseconds or microseconds. + Default value is 1us. RECORD OPTIONS -------------- @@ -84,10 +86,41 @@ RECORD OPTIONS -T:: --tasks-only:: Record only tasks-related events +-I:: +--io-only:: + Record only io-related events -g:: --callchain:: Do call-graph (stack chain/backtrace) recording +EXAMPLES +-------- + +$ perf timechart record git pull + + [ perf record: Woken up 13 times to write data ] + [ perf record: Captured and wrote 4.253 MB perf.data (~185801 samples) ] + +$ perf timechart + + Written 10.2 seconds of trace to output.svg. + +Record system-wide timechart: + + $ perf timechart record + + then generate timechart and highlight 'gcc' tasks: + + $ perf timechart --highlight gcc + +Record system-wide IO events: + + $ perf timechart record -I + + then generate timechart: + + $ perf timechart + SEE ALSO -------- linkperf:perf-record[1] |