diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/Documentation/tips.txt | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/tools/perf/Documentation/tips.txt b/tools/perf/Documentation/tips.txt new file mode 100644 index 000000000..825745a64 --- /dev/null +++ b/tools/perf/Documentation/tips.txt @@ -0,0 +1,43 @@ +For a higher level overview, try: perf report --sort comm,dso +Sample related events with: perf record -e '{cycles,instructions}:S' +Compare performance results with: perf diff [<old file> <new file>] +Boolean options have negative forms, e.g.: perf report --no-children +Customize output of perf script with: perf script -F event,ip,sym +Generate a script for your data: perf script -g <lang> +Save output of perf stat using: perf stat record <target workload> +Create an archive with symtabs to analyse on other machine: perf archive +Search options using a keyword: perf report -h <keyword> +Use parent filter to see specific call path: perf report -p <regex> +List events using substring match: perf list <keyword> +To see list of saved events and attributes: perf evlist -v +Use --symfs <dir> if your symbol files are in non-standard locations +To see callchains in a more compact form: perf report -g folded +Show individual samples with: perf script +Limit to show entries above 5% only: perf report --percent-limit 5 +Profiling branch (mis)predictions with: perf record -b / perf report +To show assembler sample contexts use perf record -b / perf script -F +brstackinsn --xed +Treat branches as callchains: perf report --branch-history +To count events in every 1000 msec: perf stat -I 1000 +Print event counts in CSV format with: perf stat -x, +If you have debuginfo enabled, try: perf report -s sym,srcline +For memory address profiling, try: perf mem record / perf mem report +For tracepoint events, try: perf report -s trace_fields +To record callchains for each sample: perf record -g +To record every process run by a user: perf record -u <user> +Skip collecting build-id when recording: perf record -B +To change sampling frequency to 100 Hz: perf record -F 100 +See assembly instructions with percentage: perf annotate <symbol> +If you prefer Intel style assembly, try: perf annotate -M intel +For hierarchical output, try: perf report --hierarchy +Order by the overhead of source file name and line number: perf report -s srcline +System-wide collection from all CPUs: perf record -a +Show current config key-value pairs: perf config --list +Show user configuration overrides: perf config --user --list +To add Node.js USDT(User-Level Statically Defined Tracing): perf buildid-cache --add `which node` +To report cacheline events from previous recording: perf c2c report +To browse sample contexts use perf report --sample 10 and select in context menu +To separate samples by time use perf report --sort time,overhead,sym +To set sample time separation other than 100ms with --sort time use --time-quantum +Add -I to perf record to sample register values, which will be visible in perf report sample context. +To show IPC for sampling periods use perf record -e '{cycles,instructions}:S' and then browse context +To show context switches in perf report sample context add --switch-events to perf record. |