lkml.org 
[lkml]   [2011]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] perf: make perf.data more self-descriptive (v5)


On 09/23/2011 07:40 AM, Stephane Eranian wrote:
>
>
> On Fri, Sep 23, 2011 at 3:36 PM, David Ahern <dsahern@gmail.com
> <mailto:dsahern@gmail.com>> wrote:
>
>
>
> On 09/23/2011 03:04 AM, Stephane Eranian wrote:
> > On Fri, Sep 23, 2011 at 10:03 AM, Pekka Enberg
> <penberg@cs.helsinki.fi <mailto:penberg@cs.helsinki.fi>> wrote:
> >> Hi Stephane!
> >>
> >> On Fri, Sep 23, 2011 at 10:31 AM, Stephane Eranian
> <eranian@google.com <mailto:eranian@google.com>> wrote:
> >>>> So how important is this information? The output is going to be
> somewhat
> >>>> awkward for very large CPU counts... :-)
> >>>>
> >>> It is useful to determine how CPUs share caches for instance.
> >>> It can get large but large, but the meta-data header is not
> printed by
> >>> default, you need to request it with the -I option.
> >>
> >> Well, sure but it blocks rest of the interesting information too.
> It seems to me
> >> that the CPU information could be truncated to some sane limit by
> default and
> >> introduce a command line option for users that really want to see
> all of it.
> >>
> > Ok, so here is a proposal:
> > - reorder the info so one liners appear first
> > - display the "truncated" info by default (no option)
> > - truncated: numa topo, cpu topo, stop after 4 cpus/nodes, print msg
>
> Earlier I gave an example for a 2 socket, quad-core with hyperthreading
> (16 cpus total):
> https://lkml.org/lkml/2011/9/6/355
> The information is repetitive. It would be better to devise a way to
> reduce the repetition versus truncate the information.
>
>
> I have modified the patch to NOT print the CPU, NUMA topology by
> default (but mentioned they are available with the -I option). The
> other bits of information are displayed systematically (no truncation).
>
> What ways would you propose to still print the info is a less-verbose
> fashion?
>

for example, sibling cores:
# CPU0 sibling cores : 0,2,4,6,8,10,12,14

you don't need to print that info for CPUs 0,2,4,6,8,10,12,14. Just
once. Maybe just:

# CPU sibling cores : 0,2,4,6,8,10,12,14

Similarly for the threads:
# CPU sibling threads: 0,8


That drops the output from 32 lines to 10.

# CPU sibling cores : 0,2,4,6,8,10,12,14
# CPU sibling cores : 1,3,5,7,9,11,13,15
# CPU sibling threads: 0,8
# CPU sibling threads: 1,9
# CPU sibling threads: 2,10
# CPU sibling threads: 3,11
# CPU sibling threads: 4,12
# CPU sibling threads: 5,13
# CPU sibling threads: 6,14
# CPU sibling threads: 7,15



\
 
 \ /
  Last update: 2011-09-23 16:11    [from the cache]
©2003-2011 Jasper Spaans