• Tony Jones's avatar
    perf scripts python: Add new compaction-times script · 84e5d89a
    Tony Jones authored
    This patch creates a new script (compaction-times) to report time
    spent in mm compaction. It is possible to report times in nanoseconds
    (default) or microseconds (-u).
    
    The option -p will break down results by process id, -pv will further
    decompose by each compaction entry/exit.
    
    For each compaction entry/exit what is reported is controlled by the
    options:
    
      -t   report only timing
      -m   report migration stats
      -ms  report migration scanner stats
      -fs  report free scanner stats
    
    The default is to report all.
    
    Entries may be further filtered by pid, pid-range or comm (regex).
    
    The script is useful when analysing workloads that compact memory. The
    most common example will be THP allocations on systems with a lot of
    uptime that has fragmented memory.
    
    This is an example of using the script to analyse a thpscale from
    mmtests which deliberately fragments memory and allocates THP in 4
    separate threads
    
      # Recording step, one of the following;
      $ perf record -e 'compaction:mm_compaction_*' ./workload
      # or:
      $ perf script record compaction-times
    
      # Reporting: basic
      total: 2444505743ns migration: moved=357738 failed=39275
      free_scanner: scanned=2705578 isolated=387875
      migration_scanner: scanned=414426 isolated=397013
    
      # Reporting: Per task stall times
      $ perf script report compaction-times -- -t -p
      total: 2444505743ns
      6384[thpscale]: 740800017ns
      6385[thpscale]: 274119512ns
      6386[thpscale]: 832961337ns
      6383[thpscale]: 596624877ns
    
      # Reporting: Per-compaction attempts for task 6385
      $ perf script report compaction-times -- -m -pv 6385
      total: 274119512ns migration: moved=14893 failed=24285
      6385[thpscale]: 274119512ns migration: moved=14893 failed=24285
      6385[thpscale].1: 3033277ns migration: moved=511 failed=1
      6385[thpscale].2: 9592094ns migration: moved=1524 failed=12
      6385[thpscale].3: 2495587ns migration: moved=512 failed=0
      6385[thpscale].4: 2561766ns migration: moved=512 failed=0
      6385[thpscale].5: 2523521ns migration: moved=512 failed=0
      ..... output continues ...
    
    Changes since v1:
    - report stats for isolate_migratepages and isolate_freepages
      (Vlastimil Babka)
    - refactor code to achieve above
    - add help text
    - output to stdout/stderr explicitly
    Signed-off-by: default avatarTony Jones <tonyj@suse.com>
    Cc: Mel Gorman <mgorman@suse.com>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Link: http://lkml.kernel.org/r/1439840932-8933-1-git-send-email-tonyj@suse.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    84e5d89a
compaction-times-record 229 Bytes