65 lines
5.1 KiB
Plaintext
65 lines
5.1 KiB
Plaintext
For a higher level overview, try: perf report --sort comm,dso
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Sample related events with: perf record -e '{cycles,instructions}:S'
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Compare performance results with: perf diff [<old file> <new file>]
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Boolean options have negative forms, e.g.: perf report --no-children
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To not accumulate CPU time of children symbols add --no-children
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Customize output of perf script with: perf script -F event,ip,sym
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Generate a script for your data: perf script -g <lang>
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Save output of perf stat using: perf stat record <target workload>
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Create an archive with symtabs to analyse on other machine: perf archive
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Search options using a keyword: perf report -h <keyword>
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Use parent filter to see specific call path: perf report -p <regex>
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List events using substring match: perf list <keyword>
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To see list of saved events and attributes: perf evlist -v
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Use --symfs <dir> if your symbol files are in non-standard locations
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To see callchains in a more compact form: perf report -g folded
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To see call chains by final symbol taking CPU time (bottom up) use perf report -G
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Show individual samples with: perf script
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Limit to show entries above 5% only: perf report --percent-limit 5
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Profiling branch (mis)predictions with: perf record -b / perf report
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To show assembler sample context control flow use perf record -b / perf report --samples 10 and then browse context
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To adjust path to source files to local file system use perf report --prefix=... --prefix-strip=...
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Treat branches as callchains: perf record -b ... ; perf report --branch-history
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Show estimate cycles per function and IPC in annotate use perf record -b ... ; perf report --total-cycles
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To count events every 1000 msec: perf stat -I 1000
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Print event counts in machine readable CSV format with: perf stat -x\;
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If you have debuginfo enabled, try: perf report -s sym,srcline
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For memory address profiling, try: perf mem record / perf mem report
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For tracepoint events, try: perf report -s trace_fields
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To record callchains for each sample: perf record -g
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If call chains don't work try perf record --call-graph dwarf or --call-graph lbr
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To record every process run by a user: perf record -u <user>
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To show inline functions in call traces add --inline to perf report
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To not record events from perf itself add --exclude-perf
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Skip collecting build-id when recording: perf record -B
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To change sampling frequency to 100 Hz: perf record -F 100
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To show information about system the samples were collected on use perf report --header
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To only collect call graph on one event use perf record -e cpu/cpu-cycles,callgraph=1/,branches ; perf report --show-ref-call-graph
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To set sampling period of individual events use perf record -e cpu/cpu-cycles,period=100001/,cpu/branches,period=10001/ ...
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To group events which need to be collected together for accuracy use {}: perf record -e {cycles,branches}' ...
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To compute metrics for samples use perf record -e '{cycles,instructions}' ... ; perf script -F +metric
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See assembly instructions with percentage: perf annotate <symbol>
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If you prefer Intel style assembly, try: perf annotate -M intel
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When collecting LBR backtraces use --stitch-lbr to handle more than 32 deep entries: perf record --call-graph lbr ; perf report --stitch-lbr
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For hierarchical output, try: perf report --hierarchy
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Order by the overhead of source file name and line number: perf report -s srcline
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System-wide collection from all CPUs: perf record -a
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Show current config key-value pairs: perf config --list
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To collect Processor Trace with samples use perf record -e '{intel_pt//,cycles}' ; perf script --call-trace or --insn-trace --xed -F +ipc (remove --xed if no xed)
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To trace calls using Processor Trace use perf record -e intel_pt// ... ; perf script --call-trace. Then use perf script --time A-B --insn-trace to look at region of interest.
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To measure approximate function latency with Processor Trace use perf record -e intel_pt// ... ; perf script --call-ret-trace
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To trace only single function with Processor Trace use perf record --filter 'filter func @ program' -e intel_pt//u ./program ; perf script --insn-trace
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Show user configuration overrides: perf config --user --list
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To add Node.js USDT(User-Level Statically Defined Tracing): perf buildid-cache --add `which node`
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To analyze cache line scalability issues use perf c2c record ... ; perf c2c report
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To browse sample contexts use perf report --sample 10 and select in context menu
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To separate samples by time use perf report --sort time,overhead,sym
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To filter subset of samples with report or script add --time X-Y or --cpu A,B,C or --socket-filter ...
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To set sample time separation other than 100ms with --sort time use --time-quantum
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Add -I to perf record to sample register values, which will be visible in perf report sample context.
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To show IPC for sampling periods use perf record -e '{cycles,instructions}:S' and then browse context
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To show context switches in perf report sample context add --switch-events to perf record.
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To show time in nanoseconds in record/report add --ns
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To compare hot regions in two workloads use perf record -b -o file ... ; perf diff --stream file1 file2
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To compare scalability of two workload samples use perf diff -c ratio file1 file2
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