Messages in this thread | | | Date | Tue, 30 Jun 2015 14:34:59 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH RFC 1/1] perf,tool: partial callgrap and time support |
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On Sun, Jun 28, 2015 at 01:47:21PM -0400, kan.liang@intel.com wrote: > From: Kan Liang <kan.liang@intel.com> > > When multiple events are sampled it may not be needed to collect > callgraphs for all of them. The sample sites are usually nearby, and > it's enough to collect the callgraphs on a reference event (such as > precise cycles or precise instructions). Similarly we also don't need > fine grained time stamps on all events, as it's enough to have time > stamps on the regular reference events. > This patchkit adds the ability to turn off callgraphs and time stamps > per event. This in term can reduce sampling overhead and the size of the > perf.data. Furthermore, it makes collecting back traces and timestamps > possible when PEBS threshold > 1, which significantly reducing the > sampling overhead especially for frequently occurring events > (https://lkml.org/lkml/2015/5/10/196). For example, A slower event with > a larger period collects back traces/timestamps. Other more events run > fast with multi-pebs. The time stamps from the slower events can be used > to order the faster events. Their backtraces can give the user enough > hint to find the right spot.
SNIP
> > 7.13% 0.03% tchain_edit [kernel.vmlinux] [k] do_nmi > | > ---do_nmi > end_repeat_nmi > f3 > f2 > f1 > main > __libc_start_main > > Signed-off-by: Kan Liang <kan.liang@intel.com> > --- > tools/perf/Documentation/perf-record.txt | 13 ++++++++ > tools/perf/builtin-record.c | 7 ++-- > tools/perf/perf.h | 2 ++ > tools/perf/util/evsel.c | 55 ++++++++++++++++++++++++++++++-- > tools/perf/util/parse-events.c | 33 +++++++++++++++++++ > tools/perf/util/parse-events.h | 3 ++ > tools/perf/util/parse-events.l | 3 ++ > tools/perf/util/parse-options.c | 2 ++ > tools/perf/util/parse-options.h | 4 +++ > 9 files changed, 116 insertions(+), 6 deletions(-)
could you please break up this patch into: - parse option changes (+description what are those new macros good for) - callchains terms addition - time term addition
thanks, jirka
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