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a7fdd30a22
Add flag +e to the itrace d (decoder debug log) option to get output only on decoding errors. The log can be very big so reducing the output to where there are decoding errors can be useful for analyzing errors. By default, the log size in that case is 16384 bytes, but can be altered by perf config e.g. perf config itrace.debug-log-buffer-size=30000 Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220905073424.3971-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
71 lines
2.6 KiB
Plaintext
71 lines
2.6 KiB
Plaintext
i synthesize instructions events
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b synthesize branches events (branch misses for Arm SPE)
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c synthesize branches events (calls only)
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r synthesize branches events (returns only)
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x synthesize transactions events
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w synthesize ptwrite events
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p synthesize power events (incl. PSB events for Intel PT)
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o synthesize other events recorded due to the use
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of aux-output (refer to perf record)
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I synthesize interrupt or similar (asynchronous) events
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(e.g. Intel PT Event Trace)
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e synthesize error events
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d create a debug log
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f synthesize first level cache events
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m synthesize last level cache events
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M synthesize memory events
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t synthesize TLB events
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a synthesize remote access events
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g synthesize a call chain (use with i or x)
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G synthesize a call chain on existing event records
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l synthesize last branch entries (use with i or x)
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L synthesize last branch entries on existing event records
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s skip initial number of events
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q quicker (less detailed) decoding
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A approximate IPC
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Z prefer to ignore timestamps (so-called "timeless" decoding)
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The default is all events i.e. the same as --itrace=ibxwpe,
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except for perf script where it is --itrace=ce
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In addition, the period (default 100000, except for perf script where it is 1)
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for instructions events can be specified in units of:
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i instructions
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t ticks
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ms milliseconds
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us microseconds
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ns nanoseconds (default)
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Also the call chain size (default 16, max. 1024) for instructions or
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transactions events can be specified.
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Also the number of last branch entries (default 64, max. 1024) for
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instructions or transactions events can be specified.
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Similar to options g and l, size may also be specified for options G and L.
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On x86, note that G and L work poorly when data has been recorded with
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large PEBS. Refer linkperf:perf-intel-pt[1] man page for details.
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It is also possible to skip events generated (instructions, branches, transactions,
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ptwrite, power) at the beginning. This is useful to ignore initialization code.
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--itrace=i0nss1000000
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skips the first million instructions.
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The 'e' option may be followed by flags which affect what errors will or
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will not be reported. Each flag must be preceded by either '+' or '-'.
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The flags are:
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o overflow
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l trace data lost
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If supported, the 'd' option may be followed by flags which affect what
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debug messages will or will not be logged. Each flag must be preceded
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by either '+' or '-'. The flags are:
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a all perf events
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e output only on errors (size configurable - see linkperf:perf-config[1])
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o output to stdout
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If supported, the 'q' option may be repeated to increase the effect.
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