84e5d89a77
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: Tony 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.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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