linux_dsm_epyc7002/tools/perf
Peter Zijlstra 506d4bc8d5 perf stat: Change noise calculation to use stddev
The current noise computation does:

 \Sum abs(n_i - avg(n)) * N^-1.5

Which is (afaik) not a regular noise function, and needs the
complete sample set available to post-process.

Change this to use a regular stddev computation which can be
done by keeping a two sums:

 stddev = sqrt( 1/N (\Sum n_i^2) - avg(n)^2 )

For which we only need to keep \Sum n_i and \Sum n_i^2.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-04 16:33:07 +02:00
..
Documentation perf tools: Add missing parameters documentation 2009-08-31 10:04:47 +02:00
util perf trace: Fix read_string() 2009-09-03 16:22:45 +02:00
.gitignore perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
builtin-annotate.c perf tools: Librarize idle thread registration 2009-08-31 10:04:48 +02:00
builtin-help.c perf: Enable more compiler warnings 2009-08-16 10:47:47 +02:00
builtin-list.c perf list: Fix large list output by using the pager 2009-08-13 09:05:48 +02:00
builtin-record.c perf trace: Sample timestamps as well 2009-09-03 15:45:49 +02:00
builtin-report.c perf tools: Librarize idle thread registration 2009-08-31 10:04:48 +02:00
builtin-stat.c perf stat: Change noise calculation to use stddev 2009-09-04 16:33:07 +02:00
builtin-top.c perf top: Show RIP only in verbose mode 2009-08-26 20:21:45 +02:00
builtin-trace.c perf trace: Fix parsing of perf.data 2009-09-03 16:19:57 +02:00
builtin.h perf tools: Factorize high level dso helpers 2009-08-12 12:02:38 +02:00
command-list.txt perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
CREDITS perf_counter tools: Add CREDITS file for Git contributors 2009-06-24 19:54:29 +02:00
design.txt perf_counter: Start documenting HAVE_PERF_COUNTERS requirements 2009-06-12 19:37:30 +02:00
Makefile perf tools: Clean up warnings list in the Makefile 2009-09-02 14:50:23 +02:00
perf.c perf tools: Add perf trace 2009-08-17 16:32:39 +02:00
perf.h perf tools: Librarize trace_event() helper 2009-08-16 23:06:45 +02:00