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| author |   Ingo Molnar <mingo@kernel.org> | 2012-10-30 09:54:41 +0100 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-10-31 12:17:49 -0200 |
| commit | 0e2af956693a8797d658d076ff4c0da4147f0131 (patch) | |
| tree | 224132ab25c0db9f1965e3b67dde294a84c78eee /tools/perf/util/PERF-VERSION-GEN | |
| parent | perf tools: Speed up the perf build time by simplifying the perf --version string generation (diff) | |
| download | wireguard-linux-0e2af956693a8797d658d076ff4c0da4147f0131.tar.xz wireguard-linux-0e2af956693a8797d658d076ff4c0da4147f0131.zip | |
perf tools: Further speed up the perf build
There's another source of overhead in the perf version string generator:
git update-index -q --refresh
... which will iterate the whole checked out tree. This can be pretty
slow on NFS volumes, but takes some time even with local SSD disks and a
fully cached kernel tree:
$ perf stat --null --repeat 3 --pre "rm -f PERF-VERSION-FILE" util/PERF-VERSION-GEN
PERF_VERSION = 3.7.rc3.g5399b3b.dirty
PERF_VERSION = 3.7.rc3.g5399b3b.dirty
PERF_VERSION = 3.7.rc3.g5399b3b.dirty
Performance counter stats for 'util/PERF-VERSION-GEN' (3 runs):
0.306999221 seconds time elapsed ( +- 0.56% )
So remove the .dirty differentiator as well - it adds little information
because locally patched git trees are common, but seldom are the perf
tools modified.
So a lot of version strings are reported as 'dirty' while in fact they
are pristine perf builds. For example 99% of my perf builds are not
patched but the kernel tree is slightly patched, which adds the .dirty
tag.
Eliminating that tag speeds up version generation by another order of
magnitude:
$ perf stat --null --repeat 3 --sync --pre "rm -f PERF-VERSION-FILE" util/PERF-VERSION-GEN
PERF_VERSION = 3.7.rc3.g4b0bd3
PERF_VERSION = 3.7.rc3.g4b0bd3
PERF_VERSION = 3.7.rc3.g4b0bd3
Performance counter stats for 'util/PERF-VERSION-GEN' (3 runs):
0.021270923 seconds time elapsed ( +- 1.94% )
(Also clean up some of the comments around this code.)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Borislav Petkov <bp@amd64.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20121030085441.GC8245@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/PERF-VERSION-GEN')
| -rwxr-xr-x | tools/perf/util/PERF-VERSION-GEN | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/tools/perf/util/PERF-VERSION-GEN b/tools/perf/util/PERF-VERSION-GEN index f6e8ee29f2ae..ac418a1255e6 100755 --- a/tools/perf/util/PERF-VERSION-GEN +++ b/tools/perf/util/PERF-VERSION-GEN @@ -9,17 +9,12 @@ GVF=${OUTPUT}PERF-VERSION-FILE LF=' ' +# # First check if there is a .git to get the version from git describe -# otherwise try to get the version from the kernel makefile +# otherwise try to get the version from the kernel Makefile +# if test -d ../../.git -o -f ../../.git && - VN=$(echo $(git tag -l "v[0-9].[0-9]*" | tail -1)"-g"$(git log -1 --abbrev=4 --pretty=format:"%h" HEAD) 2>/dev/null) && - case "$VN" in - *$LF*) (exit 1) ;; - v[0-9]*) - git update-index -q --refresh - test -z "$(git diff-index --name-only HEAD --)" || - VN="$VN-dirty" ;; - esac + VN=$(echo $(git tag -l "v[0-9].[0-9]*" | tail -1)"-g"$(git log -1 --abbrev=4 --pretty=format:"%h" HEAD) 2>/dev/null) then VN=$(echo "$VN" | sed -e 's/-/./g'); else |