Messages in this thread | | | Date | Wed, 28 Aug 2013 15:38:28 +0200 | Subject | Re: [PATCH] perf mem: add priv level filtering support | From | Stephane Eranian <> |
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On Wed, Aug 28, 2013 at 3:27 PM, Arnaldo Carvalho de Melo <acme@redhat.com> wrote: > Em Mon, Aug 26, 2013 at 04:21:44PM -0600, David Ahern escreveu: >> On 8/26/13 7:11 AM, Stephane Eranian wrote: > >> >This patch adds the -u -and -k options to perf to allow >> >filtering of load/store sampling based on priv levels. >> >This may not be supported by all HW platforms. > > >> >+++ b/tools/perf/Documentation/perf-mem.txt >> >+-k:: >> >+ Only sample loads/stores at the user level (default: user + kernel) >> >+-u:: >> >+ Only sample loads/stores at the kernel level (default: user + kernel) > >> Are the descriptions backwards? In the commit message yuo have -u >> means user level and -k means kernel level; the help message here >> seems backwards. > > Looks like it is reversed, yes. > >> >+ OPT_BOOLEAN('u', "user-level", &mem.user, "include user-level accesses"), >> >+ OPT_BOOLEAN('k', "kernel-level", &mem.kernel, "include kernel-level accesses"), > > And its not clear to say that using -u will _exclude_ kernel samples, > just that it includes user samples, perf top has: > > -K, --hide_kernel_symbols hide kernel symbols > -U, --hide_user_symbols hide user symbols > > So perhaps we should change both to (and add this to 'report' as well): > > -U, --hide_kernel_symbols hide kernel symbols > -K, --hide_user_symbols hide user symbols >
Well, I don't know what perf top does here but I don't want to hide the samples. I simply don't want to collect them (do not appear in the perf.data file). If that's what is happening in perf top, then I'll be glad to use the same options.
> To state that: > > perf top -K > and > perf top --hide_user_symbols > > Are equivalent and asks for 'kernel only' samples, like it seems its the > intent (filtering) of Stephane here, and seems to clarify things? > > - Arnaldo
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