Commit-ID: 0e2af956693a8797d658d076ff4c0da4147f0131
Gitweb: http://git.kernel.org/tip/0e2af956693a8797d658d076ff4c0da4147f0131
Author: Ingo Molnar <mi...@kernel.org>
AuthorDate: Tue, 30 Oct 2012 09:54:41 +0100
Committer: Arnaldo Carvalho de Melo <a...@redhat.com>
CommitDate: Wed, 31 Oct 2012 12:17:49 -0200
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 <mi...@kernel.org>
Cc: Andrew Vagin <ava...@openvz.org>
Cc: Borislav Petkov <b...@amd64.org>
Cc: David Howells <dhowe...@redhat.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Stephane Eranian <eran...@gmail.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Link: http://lkml.kernel.org/r/20121030085441.gc8...@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
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 f6e8ee2..ac418a1 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
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