Re: [GIT PULL 00/52] New Tool: perf c2c

Jiri Olsa
2016-10-23T11:05:51Z

On Sat, Oct 22, 2016 at 10:28:06AM +0200, Ingo Molnar wrote:

SNIP

> > tools/perf/ui/browsers/hists.h | 1 +
> > tools/perf/util/hist.c | 1 +
> > tools/perf/util/hist.h | 1 +
> > tools/perf/util/mem-events.c | 128 ++
> > tools/perf/util/mem-events.h | 37 +
> > tools/perf/util/sort.c | 2 +-
> > tools/perf/util/sort.h | 1 +
> > 13 files changed, 3210 insertions(+), 2 deletions(-)
> > create mode 100644 tools/perf/Documentation/perf-c2c.txt
> > create mode 100644 tools/perf/builtin-c2c.c
>
> Pulled the perf-c2c-for-mingo-20161021 tag, thanks a lot Arnaldo!
>
> I can see some teething problems. For example if I run it on an older kernel (v4.4
> distro kernel), I get this:
>
> triton:~/tip> perf c2c record perf bench sched pipe
> # Running 'sched/pipe' benchmark:
> # Executed 1000000 pipe operations between two processes
>
> Total time: 12.001 [sec]
>
> 12.001919 usecs/op
> 83320 ops/sec
> [ perf record: Woken up 18 times to write data ]
> [ perf record: Captured and wrote 5.356 MB perf.data (69804 samples) ]
>
> but there's no 'perf c2c report' TUI output at all:
>
> Shared Data Cache Line Table (0 entries, sorted on remote HITMs)
> Total Rmt ----- LLC Load Hitm ----- ---- Store Reference ---- --- Load Dram ---- LLC Total ----- Core Load Hit ----- -- LLC Load Hit -
> Index Cacheline records Hitm Total Lcl Rmt Total L1Hit L1Miss Lcl Rmt Ld Miss Loads FB L1 L2 Llc Rm
>
> and just an empty screen.
>
> If I do 'perf report' I get two events:
>
> Available samples
> 24K cpu/mem-loads,ldlat=30/P
> 45K cpu/mem-stores/P
>
> and both have some real data.
>
> What am I missing?

hm, most likely you did not generate any remote HITMs.. if it was on the laptop?
you might get some results for local HITMs with -d option:

$ perf c2c report -d lcl

the default display/filter is for Remote HITMs.. perhaps we could be
smart enough and switch to local when we found no data for remote

jirka