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

[Jiri Olsa]

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