The kernel perf subsystem has to IPI to the target CPU for many
operations. On systems with many CPUs and when managing many events the
overhead can be dominated by lots of IPIs.
An alternative is to set up CPU affinity in the perf tool, then set up
all the events for that CPU, and then move on to the next CPU.
Add some affinity management infrastructure to enable such a model.
Used in followon patches.
Committer notes:
Use zfree() in some places, add missing stdbool.h header, some minor
coding style changes.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191121001522.180827-3-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
pmu.c does a lot of redundant /sys accesses while parsing aliases
and probing for PMUs. On large systems with a lot of PMUs this
can get expensive (>2s):
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
27.25 1.227847 8 160888 16976 openat
26.42 1.190481 7 164224 164077 stat
Add a cache to remember if specific file names exist or don't
exist, which eliminates most of this overhead.
Also optimize some stat() calls to be slightly cheaper access()
Resulting in:
0.18 0.004166 2 1851 305 open
0.08 0.001970 2 829 622 access
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191121001522.180827-2-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We have already implemented some block-info related functions.
Now it's time to do some cleanup, refactoring and move the
functions and structures to new block-info.h/block-info.c.
v4:
---
Move code for skipping column length calculation to patch:
'perf diff: Don't use hack to skip column length calculation'
v3:
---
1. Rename the patch title
2. Rename from block.h/block.c to block-info.h/block-info.c
3. Move more common part to block-info, such as
block_info__process_sym.
4. Remove the nasty hack for skipping calculation of column
length
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191107074719.26139-3-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add utilities to help checking capabilities of the running procss. Make
perf link with libcap, if it is available. If no libcap-dev[el],
fallback to the geteuid() == 0 test used before.
Committer notes:
$ perf test python
18: 'import perf' in python : FAILED!
$ perf test -v python
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
18: 'import perf' in python :
--- start ---
test child forked, pid 23288
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: cap_get_flag
test child finished with -1
---- end ----
'import perf' in python: FAILED!
$
This happens because differently from the perf binary generated with
this patch applied:
$ ldd /tmp/build/perf/perf | grep libcap
libcap.so.2 => /lib64/libcap.so.2 (0x00007f724a4ef000)
$
The python binding isn't linking with libcap:
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$
So add 'cap' to the 'extra_libraries' variable in
tools/perf/util/setup.py, and rebuild:
$ perf test python
18: 'import perf' in python : Ok
$
If we explicitely disable libcap it also continues to work:
$ make NO_LIBCAP=1 -C tools/perf O=/tmp/build/perf install-bin
$ ldd /tmp/build/perf/perf | grep libcap
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$ perf test python
18: 'import perf' in python : Ok
$
Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
[ split from a larger patch ]
Link: http://lkml.kernel.org/r/8a1e76cf5c7c9796d0d4d240fbaa85305298aafa.1565188228.git.ilubashe@akamai.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Just like the BPF guys did when faced with failures with map creation,
etc, i.e. their solution is:
tools/testing/selftests/bpf/bpf_rlimit.h
For perf use this function in 'perf test' and in 'perf trace'.
Make it bump to 4 times the current value, if it fails twice the current
value and if it still fails, warn that things like BPF map creation may
fail, to help in diagnosing the problem.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-muvqef2i7n6pzqbmu7tn2d2y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This came from the kernel lib/argv_split.c, so move it to
tools/lib/argv_split.c, to get it closer to the kernel structure.
We need to audit the usage of argv_split() to figure out if it is really
necessary to do have one allocation per argv[] entry, looking at one of
its users I guess that is not the case and we probably are even leaking
those allocations by not using argv_free() judiciously, for later.
With this we further remove stuff from tools/perf/util/, reducing the
perf specific codebase and encouraging other tools/ code to use these
routines so as to keep the style and constructs used with the kernel.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-j479s1ive9h75w5lfg16jroz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We got the sane_ctype.h headers from git and kept using it so far, but
since that code originally came from the kernel sources to the git
sources, perhaps its better to just use the one in the kernel, so that
we can leverage tools/perf/check_headers.sh to be notified when our copy
gets out of sync, i.e. when fixes or goodies are added to the code we've
copied.
This will help with things like tools/lib/string.c where we want to have
more things in common with the kernel, such as strim(), skip_spaces(),
etc so as to go on removing the things that we have in tools/perf/util/
and instead using the code in the kernel, indirectly and removing things
like EXPORT_SYMBOL(), etc, getting notified when fixes and improvements
are made to the original code.
Hopefully this also should help with reducing the difference of code
hosted in tools/ to the one in the kernel proper.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7k9868l713wqtgo01xxygn12@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make struct cpu_topo global and rename it to 'struct cpu_topology', so
that it can be used from the 'perf record' command in the following
patches.
Add the following interface functions to load/free cpu topology details:
struct cpu_topology *cpu_topology__new(void);
void cpu_topology__delete(struct cpu_topology *tp);
Move it to a separate source file cputopo.c together with numa related
object in the following patches.
No functional change, the new interface will be used in upcoming changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190219095815.15931-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa
Andi Kleen
Jin Yao
Arnaldo Carvalho de Melo
Igor Lubashev
Alexey Budankov
Mathieu Poirier