When make runs it tries to update the Makefile rules by reading all of
included Makefiles. During the perf build it checks PERF-VERSION-FILE
to get the current version number. But it triggers Makefile update so
that make runs again with the update Makefile and, in turn, users will
see duplicate CHK message on the second path.
Running make with -d option for debugging tells me this:
GNU Make 3.82
Built for x86_64-redhat-linux-gnu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Reading makefiles...
Reading makefile `Makefile'...
Reading makefile `../scripts/Makefile.include' (search path) (no ~ expansion)...
Reading makefile `config/utilities.mak' (search path) (no ~ expansion)...
Reading makefile `PERF-VERSION-FILE' (search path) (don't care) (no ~ expansion)...
Reading makefile `config/feature-tests.mak' (search path) (don't care) (no ~ expansion)...
CHK -fstack-protector-all
CHK -Wstack-protector
CHK -Wvolatile-register-var
...
Updating makefiles....
Considering target file `PERF-VERSION-FILE'.
Must remake target `PERF-VERSION-FILE'.
Invoking recipe from Makefile:52 to update target `PERF-VERSION-FILE'.
Putting child 0x14037a0 (PERF-VERSION-FILE) PID 31925 on the chain.
Live child 0x14037a0 (PERF-VERSION-FILE) PID 31925
PERF_VERSION = 3.8.rc3.gf751db6
Reaping winning child 0x14037a0 PID 31925
Removing child 0x14037a0 PID 31925 from chain.
Successfully remade target file `PERF-VERSION-FILE'.
...
Re-executing[1]: make -d <------------ here
GNU Make 3.82
Built for x86_64-redhat-linux-gnu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Reading makefiles...
Reading makefile `Makefile'...
Reading makefile `../scripts/Makefile.include' (search path) (no ~ expansion)...
Reading makefile `config/utilities.mak' (search path) (no ~ expansion)...
Reading makefile `PERF-VERSION-FILE' (search path) (don't care) (no ~ expansion)...
Reading makefile `config/feature-tests.mak' (search path) (don't care) (no ~ expansion)...
CHK -fstack-protector-all
CHK -Wstack-protector
CHK -Wvolatile-register-var
...
Actually PERF-VERSION-FILE is used only for perf.c to #define
PERF_VERSION macro. So make it like a C header file and include it
during compiling the perf.c file will remove the need of being
included into Makefile. Hench no need to update the Makefile and no
CHK lines anymore.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1358337594-10916-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 generating the perf version from the kernel version using 'make
kernelver' it is necessary to clear out any MAKEFLAGS otherwise they may
trigger additional output which pollute the contents.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Some versions of grep don't treat '\s' properly. When building perf on such
systems and using a kernel tarball the perf version is unable to be determined
from the main kernel Makefile and the user is left with a version of '..'.
Replacing the use of '\s' with '[[:space:]]', which should work in all grep
versions, gives a usable version number.
Reported-by: Tapan Dhimant <tdhimant@akamai.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tapan Dhimant <tdhimant@akamai.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@kernel.org
LKML-Reference: <1300241800-30281-1-git-send-email-johunt@akamai.com>
Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This gets rid of the default version fallback for Perf and
changes it so that it returns the version of the kernel from
it's Makefile (if sources were not from git, ie. if it was
downloaded from a tarball)
Signed-off-by: Thavidu Ranatunga <tharan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1278316815-6099-2-git-send-email-tharan@au1.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Changes the Perf --version string such that it shows the kernel
version as suggested by Ingo as follows:
That way the perf that comes with v2.6.34 will be:
perf version v2.6.34
while interim versions will have the version of the interim
kernel - for example:
perf version v2.6.35-rc4-70-g39ef13a
This functionality was already in the perf version generator
file except that it was looking for a .git in the perf directory
instead of the kernel directory.
Signed-off-by: Thavidu Ranatunga <tharan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1278316815-6099-1-git-send-email-tharan@au1.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Avoiding polluting the source tree with build files.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We released the first version of perf with 0.0.1 in v2.6.31,
time to double our version number to 0.0.2 ;-)
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Several people have suggested that 'perf' has become a full-fledged
tool that should be moved out of Documentation/. Move it to the
(new) tools/ directory.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
