linux-stable/tools/perf
Namhyung Kim a1bf23052b perf stat: Take cgroups into account for shadow stats
As of now it doesn't consider cgroups when collecting shadow stats and
metrics so counter values from different cgroups will be saved in a same
slot.  This resulted in incorrect numbers when those cgroups have
different workloads.

For example, let's look at the scenario below: cgroups A and C runs same
workload which burns a cpu while cgroup B runs a light workload.

  $ perf stat -a -e cycles,instructions --for-each-cgroup A,B,C  sleep 1

   Performance counter stats for 'system wide':

     3,958,116,522      cycles                A
     6,722,650,929      instructions          A #    2.53  insn per cycle
         1,132,741      cycles                B
           571,743      instructions          B #    0.00  insn per cycle
     4,007,799,935      cycles                C
     6,793,181,523      instructions          C #    2.56  insn per cycle

       1.001050869 seconds time elapsed

When I run 'perf stat' with single workload, it usually shows IPC around
1.7.  We can verify it (6,722,650,929.0 / 3,958,116,522 = 1.698) for cgroup A.

But in this case, since cgroups are ignored, cycles are averaged so it
used the lower value for IPC calculation and resulted in around 2.5.

  avg cycle: (3958116522 + 1132741 + 4007799935) / 3 = 2655683066
  IPC (A)  :  6722650929 / 2655683066 = 2.531
  IPC (B)  :      571743 / 2655683066 = 0.0002
  IPC (C)  :  6793181523 / 2655683066 = 2.557

We can simply compare cgroup pointers in the evsel and it'll be NULL
when cgroups are not specified.  With this patch, I can see correct
numbers like below:

  $ perf stat -a -e cycles,instructions --for-each-cgroup A,B,C  sleep 1

  Performance counter stats for 'system wide':

     4,171,051,687      cycles                A
     7,219,793,922      instructions          A #    1.73  insn per cycle
         1,051,189      cycles                B
           583,102      instructions          B #    0.55  insn per cycle
     4,171,124,710      cycles                C
     7,192,944,580      instructions          C #    1.72  insn per cycle

       1.007909814 seconds time elapsed

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210115071139.257042-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-01-15 17:28:27 -03:00
..
arch perf tools: Update s390's syscall.tbl copy from the kernel sources 2020-12-24 09:24:20 -03:00
bench tools arch: Update arch/x86/lib/mem{cpy,set}_64.S copies used in 'perf bench mem memcpy' 2020-11-12 17:55:41 -03:00
Documentation perf sort: Add sort option for data page size 2020-12-19 17:52:24 -03:00
examples/bpf perf bpf examples: Fix bpf.h header include directive in 5sec.c example 2021-01-15 16:31:46 -03:00
include/bpf
jvmti perf jvmti: Remove redundant jitdump line table entries 2020-05-29 16:51:38 -03:00
pmu-events perf vendor events: Add JSON metrics for imx8mm DDR Perf 2020-12-17 14:36:17 -03:00
python tweewide: Fix most Shebang lines 2020-12-08 23:30:04 +09:00
scripts perf script: Add min, max to futex-contention output, in addition to avg 2020-09-23 12:58:53 -03:00
tests perf test: Fix shadow stat test for non-bash shells 2021-01-15 16:31:46 -03:00
trace tools arch x86: Sync the msr-index.h copy with the kernel sources 2020-12-24 09:24:19 -03:00
ui perf evlist: Use the right prefix for 'struct evlist' event selection methods 2020-11-30 15:01:08 -03:00
util perf stat: Take cgroups into account for shadow stats 2021-01-15 17:28:27 -03:00
.gitignore
Build
builtin-annotate.c perf evlist: Use the right prefix for 'struct evlist' event group methods 2020-11-30 15:00:12 -03:00
builtin-bench.c perf bench: Add build-id injection benchmark 2020-10-13 10:59:42 -03:00
builtin-buildid-cache.c perf tools: Pass build_id object to build_id__sprintf() 2020-10-14 08:46:22 -03:00
builtin-buildid-list.c
builtin-c2c.c perf c2c: Support AUX trace 2020-11-11 12:27:06 -03:00
builtin-config.c
builtin-data.c perf data: Add support to store time of day in CTF data conversion 2020-08-06 09:43:37 -03:00
builtin-diff.c perf evlist: Use the right prefix for 'struct evlist' diff methods 2020-11-30 15:18:48 -03:00
builtin-evlist.c perf evlist: Support pipe mode display 2020-12-17 14:36:17 -03:00
builtin-ftrace.c perf evlist: Use the right prefix for 'struct evlist' create maps methods 2020-11-30 14:56:52 -03:00
builtin-help.c
builtin-inject.c Merge remote-tracking branch 'torvalds/master' into perf/core 2020-11-30 08:56:55 -03:00
builtin-kallsyms.c
builtin-kmem.c perf evlist: Use the right prefix for 'struct evlist' 'find' methods 2020-11-30 09:48:07 -03:00
builtin-kvm.c perf evlist: Use the right prefix for 'struct evlist' mmap pages parsing method 2020-11-30 15:15:30 -03:00
builtin-list.c perf list: Remove dead code in argument check 2020-09-09 11:12:10 -03:00
builtin-lock.c perf lock: Don't free "lock_seq_stat" if read_count isn't zero 2020-11-12 17:55:41 -03:00
builtin-mem.c perf mem: Factor out a function to generate sort order 2020-12-19 17:53:29 -03:00
builtin-probe.c perf probe: Do not show the skipped events 2020-05-28 10:03:24 -03:00
builtin-record.c perf record: Support new sample type for data page size 2020-12-17 14:36:16 -03:00
builtin-report.c perf report: Support --header-only for pipe mode 2020-12-17 14:36:17 -03:00
builtin-sched.c perf evlist: Use the right prefix for 'struct evlist' 'find' methods 2020-11-30 09:48:07 -03:00
builtin-script.c perf script: Support data page size 2020-12-19 17:04:39 -03:00
builtin-stat.c perf stat aggregation: Add separate core member 2020-12-24 10:05:25 -03:00
builtin-timechart.c perf tools: Replace zero-length array with flexible-array 2020-05-28 10:03:27 -03:00
builtin-top.c perf evlist: Use the right prefix for 'struct evlist' mmap pages parsing method 2020-11-30 15:15:30 -03:00
builtin-trace.c perf evlist: Use the right prefix for 'struct evlist' mmap pages parsing method 2020-11-30 15:15:30 -03:00
builtin-version.c perf version: Add a feature for libpfm4 2020-11-04 09:42:40 -03:00
builtin.h
check-headers.sh perf s390: Move syscall.tbl check into check-headers.sh 2020-12-24 09:24:20 -03:00
command-list.txt
CREDITS
design.txt perf tools: Support CAP_PERFMON capability 2020-04-16 12:19:08 -03:00
Makefile
Makefile.config perf tools: Remove LTO compiler options when building perl support 2020-11-03 08:24:54 -03:00
Makefile.perf tools: Factor HOSTCC, HOSTLD, HOSTAR definitions 2020-11-11 12:18:22 -08:00
MANIFEST
perf-archive.sh
perf-completion.sh
perf-read-vdso.c
perf-sys.h perf tests: Call test_attr__open() directly 2020-09-10 11:55:37 -03:00
perf-with-kcore.sh
perf.c
perf.h