| perf-diff(1) | |
| ============ | |
| NAME | |
| ---- | |
| perf-diff - Read two perf.data files and display the differential profile | |
| SYNOPSIS | |
| -------- | |
| [verse] | |
| 'perf diff' [oldfile] [newfile] | |
| DESCRIPTION | |
| ----------- | |
| This command displays the performance difference amongst two perf.data files | |
| captured via perf record. | |
| If no parameters are passed it will assume perf.data.old and perf.data. | |
| The differential profile is displayed only for events matching both | |
| specified perf.data files. | |
| OPTIONS | |
| ------- | |
| -D:: | |
| --dump-raw-trace:: | |
| Dump raw trace in ASCII. | |
| -m:: | |
| --modules:: | |
| Load module symbols. WARNING: use only with -k and LIVE kernel | |
| -d:: | |
| --dsos=:: | |
| Only consider symbols in these dsos. CSV that understands | |
| file://filename entries. | |
| -C:: | |
| --comms=:: | |
| Only consider symbols in these comms. CSV that understands | |
| file://filename entries. | |
| -S:: | |
| --symbols=:: | |
| Only consider these symbols. CSV that understands | |
| file://filename entries. | |
| -s:: | |
| --sort=:: | |
| Sort by key(s): pid, comm, dso, symbol. | |
| -t:: | |
| --field-separator=:: | |
| Use a special separator character and don't pad with spaces, replacing | |
| all occurrences of this separator in symbol names (and other output) | |
| with a '.' character, that thus it's the only non valid separator. | |
| -v:: | |
| --verbose:: | |
| Be verbose, for instance, show the raw counts in addition to the | |
| diff. | |
| -f:: | |
| --force:: | |
| Don't complain, do it. | |
| --symfs=<directory>:: | |
| Look for files with symbols relative to this directory. | |
| -b:: | |
| --baseline-only:: | |
| Show only items with match in baseline. | |
| -c:: | |
| --compute:: | |
| Differential computation selection - delta,ratio,wdiff (default is delta). | |
| If '+' is specified as a first character, the output is sorted based | |
| on the computation results. | |
| See COMPARISON METHODS section for more info. | |
| -p:: | |
| --period:: | |
| Show period values for both compared hist entries. | |
| -F:: | |
| --formula:: | |
| Show formula for given computation. | |
| COMPARISON METHODS | |
| ------------------ | |
| delta | |
| ~~~~~ | |
| If specified the 'Delta' column is displayed with value 'd' computed as: | |
| d = A->period_percent - B->period_percent | |
| with: | |
| - A/B being matching hist entry from first/second file specified | |
| (or perf.data/perf.data.old) respectively. | |
| - period_percent being the % of the hist entry period value within | |
| single data file | |
| ratio | |
| ~~~~~ | |
| If specified the 'Ratio' column is displayed with value 'r' computed as: | |
| r = A->period / B->period | |
| with: | |
| - A/B being matching hist entry from first/second file specified | |
| (or perf.data/perf.data.old) respectively. | |
| - period being the hist entry period value | |
| wdiff | |
| ~~~~~ | |
| If specified the 'Weighted diff' column is displayed with value 'd' computed as: | |
| d = B->period * WEIGHT-A - A->period * WEIGHT-B | |
| - A/B being matching hist entry from first/second file specified | |
| (or perf.data/perf.data.old) respectively. | |
| - period being the hist entry period value | |
| - WEIGHT-A/WEIGHT-B being user suplied weights in the the '-c' option | |
| behind ':' separator like '-c wdiff:1,2'. | |
| SEE ALSO | |
| -------- | |
| linkperf:perf-record[1] |