lkml.org 
[lkml]   [2016]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] perf diff: bug fix, donot overwrite valid build id
Em Mon, Dec 19, 2016 at 02:53:30PM +0000, Liang, Kan escreveu:
> Hi Arnaldo,
>
> Ping
>
> Are you OK with the fix?

Yeah, looks ok, will merge it.

- Arnaldo

> Thanks,
> Kan
>
> >
> > From: Kan Liang <kan.liang@intel.com>
> >
> > Fixes a perf diff regression issue which was introduced by commit
> > 5baecbcd9c9a ("perf symbols: we can now read separate debug-info files
> > based on a build ID")
> >
> > The binary name could be same when perf diff different binaries. Build id is
> > used to distinguish between them.
> > However, the previous patch assumes the same binary name has same
> > build id. So it overwrites the build id according to the binary name,
> > regardless of whether the build id is set or not.
> >
> > Check the has_build_id in dso__load. If the build id is already set, use it.
> >
> > Before the fix applies,
> > sudo ./perf diff 1.perf.data 2.perf.data # Event 'cycles'
> > #
> > # Baseline Delta Shared Object Symbol
> > # ........ ....... ................ .............................
> > #
> > 99.83% -99.80% tchain_edit [.] f2
> > 0.12% +99.81% tchain_edit [.] f3
> > 0.02% -0.01% [ixgbe] [k] ixgbe_read_reg
> >
> > After the fix applies,
> > sudo ./perf diff 1.perf.data 2.perf.data # Event 'cycles'
> > #
> > # Baseline Delta Shared Object Symbol
> > # ........ ....... ................ .............................
> > #
> > 99.83% +0.10% tchain_edit [.] f3
> > 0.12% -0.08% tchain_edit [.] f2
> >
> > Signed-off-by: Kan Liang <kan.liang@intel.com>
> > ---
> > tools/perf/util/symbol.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index
> > df2482b..dc93940 100644
> > --- a/tools/perf/util/symbol.c
> > +++ b/tools/perf/util/symbol.c
> > @@ -1459,7 +1459,8 @@ int dso__load(struct dso *dso, struct map *map)
> > * Read the build id if possible. This is required for
> > * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
> > */
> > - if (is_regular_file(dso->long_name) &&
> > + if (!dso->has_build_id &&
> > + is_regular_file(dso->long_name) &&
> > filename__read_build_id(dso->long_name, build_id,
> > BUILD_ID_SIZE) > 0)
> > dso__set_build_id(dso, build_id);
> >
> > --
> > 2.4.3

\
 
 \ /
  Last update: 2016-12-19 19:39    [W:0.043 / U:0.684 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site