If git is installed we'll have a 'perf --version' output of this form:
$ make -j8 -C tools/perf/ O=/home/acme/git/build/perf install
$ perf --version
perf version 3.7.rc3.g3afad6
Now on a machine without git installed:
$ mv /home/acme/bin/git /home/acme/bin/git.OFF
$ make -j8 -C tools/perf/ O=/home/acme/git/build/perf install
$ perf --version
perf version 3.7.0-rc2
That is, no error message due to git not being installed will appear on the
screen and instead the version string in the top level Makefile will be
used.
Requested-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-am6yp6phvxyjmyndxogpunjv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
Building perf is pretty slow on trees that have a lot of commits
relative to the nearest Git tag. This slowness manifests itself during
version string generation:
$ perf stat --null --repeat 3 --sync --pre "rm -f PERF-VERSION-FILE" util/PERF-VERSION-GEN
PERF_VERSION = 3.7.rc3.1458.g5399b3b
PERF_VERSION = 3.7.rc3.1458.g5399b3b
PERF_VERSION = 3.7.rc3.1458.g5399b3b
Performance counter stats for 'util/PERF-VERSION-GEN' (3 runs):
2.857503976 seconds time elapsed ( +- 0.22% )
The build can be even slower than that, when one over NFS volumes.
The reason for the slowness is that util/PERF-VERSION-GEN uses "git
describe" to generate the string, which has to count the "number of
commits distance" from the nearest tag - the ".1458." count in the
output above. For that Git had to extract and decompress 1458 Git
objects, which takes time and bandwidth.
But this "number of commits" value is mostly irrelevant in practice. We
either want to know an approximate tag name, or we want to know the
precise sha1.
So this patch simplifies the version string to:
PERF_VERSION = 3.7.rc3.g5399b3b.dirty
which speeds up the version string generation script by an order of
magnitude:
$ perf stat --null --repeat 3 --sync --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):
0.307633559 seconds time elapsed ( +- 0.84% )
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/20121030084600.GB8245@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When perf detects no libelf during the build, it'll use internal mini
elf parser instead of libelf. But as it only supports minimal
functionalities, it also disables support to 'probe' builtin command.
Currently it didn't warned to user. Fix it.
$ sudo apt-get remove libelf-dev
$ make
CHK -fstack-protector-all
CHK -Wstack-protector
CHK -Wvolatile-register-var
CHK bionic
CHK libelf
CHK glibc
Makefile:491: No libelf found, disables 'probe' tool, please install elfutils-libelf-devel/libelf-dev
CHK libunwind
CHK libaudit
$ make NO_LIBELF=1
CHK -fstack-protector-all
CHK -Wstack-protector
CHK -Wvolatile-register-var
CHK bionic
CHK libaudit
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-8ww8zc4hhpxabfskxs3u5ede@git.kernel.org
[ committer note: The package needed is elfutils-libelf-devel, not elfutils-devel ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Create a script browser, so that user can check all the available
scripts for current perf data file and run them inside the main perf
report or annotation browsers, for all perf samples or for samples
belong to one thread/symbol.
Please be noted: current script browser is only for report use, and
doesn't cover the record phase, IOW it must run against one existing
perf data file.
The work flow is, users can use function key to list all the available
scripts for current perf data file in system and chose one, which will
be executed with popen("perf script -s xxx.xx",) and all the output
lines are put into one ui browser, pressing 'q' or left arrow key will
make it return to previous browser.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1351569369-26732-4-git-send-email-feng.tang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As suggested by Arnaldo, many scripts have their own usages and need
capture specific events or tracepoints, so only those scripts whose
target events match the events in current perf data file should be
listed in the script browser menu.
This patch will add the event match checking, by opening "xxx-record"
script to cherry pick out all events name and comparing them with
those inside the perf data file.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1351569369-26732-3-git-send-email-feng.tang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently many perf commands annotate/evlist/report/script/lock etc all
support "-i" option to chose a specific perf data, and all of them
create a local "input_name" to save the file name for that perf data.
Since most of these commands need it, we can add a global variable for
it, also it can some other benefits:
1. When calling script browser inside hists/annotation browser, it needs
to know the perf data file name to run that script.
2. For further feature like runtime switching to another perf data file,
this variable can also help.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1351569369-26732-2-git-send-email-feng.tang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa
Feng Tang
Andi Kleen
Arnaldo Carvalho de Melo
Ingo Molnar
Joonsoo Kim
Namhyung Kim