Commit-ID: 0e2af956693a8797d658d076ff4c0da4147f0131 Gitweb: http://git.kernel.org/tip/0e2af956693a8797d658d076ff4c0da4147f0131 Author: Ingo Molnar <mingo@xxxxxxxxxx> AuthorDate: Tue, 30 Oct 2012 09:54:41 +0100 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> 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 <mingo@xxxxxxxxxx> Cc: Andrew Vagin <avagin@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Link: http://lkml.kernel.org/r/20121030085441.GC8245@xxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html