linux/tools/perf
Andi Kleen d96645821e perf pmu: Use file system cache to optimize sysfs access
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>
2019-11-28 08:08:38 -03:00
..
arch perf maps: Rename map_groups.h to maps.h 2019-11-26 11:07:46 -03:00
bench perf env: Remove needless cpumap.h header 2019-09-20 09:19:21 -03:00
Documentation perf intel-pt: Add support for recording AUX area samples 2019-11-22 10:48:13 -03:00
examples/bpf
include/bpf
jvmti perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy() 2019-10-15 11:47:38 -03:00
lib perf evsel: Avoid close(-1) 2019-11-06 15:43:05 -03:00
pmu-events perf vendor events power9: Fix commas so PMU event files are valid JSON 2019-11-12 15:26:55 -03:00
python
scripts perf scripts python: exported-sql-viewer.py: Fix use of TRUE with SQLite 2019-11-13 09:13:16 -03:00
tests perf tests: Rename tests/map_groups.c to tests/maps.c 2019-11-26 11:07:46 -03:00
trace perf trace: Wire up strarray__strtoul_flags() 2019-10-19 15:35:02 -03:00
ui perf maps: Rename map_groups.h to maps.h 2019-11-26 11:07:46 -03:00
util perf pmu: Use file system cache to optimize sysfs access 2019-11-28 08:08:38 -03:00
.gitignore perf: Update .gitignore file 2019-08-31 22:27:52 -03:00
Build
builtin-annotate.c pref tools: Make 'struct addr_map_symbol' contain 'struct map_symbol' 2019-11-12 08:20:53 -03:00
builtin-bench.c perf tools: Remove perf.h from source files not needing it 2019-08-29 17:38:32 -03:00
builtin-buildid-cache.c perf session: Return error code for perf_session__new() function on failure 2019-09-20 15:58:11 -03:00
builtin-buildid-list.c perf session: Return error code for perf_session__new() function on failure 2019-09-20 15:58:11 -03:00
builtin-c2c.c perf c2c: Fix memory leak in build_cl_output() 2019-10-15 12:08:13 -03:00
builtin-config.c perf tools: Remove util.h from where it is not needed 2019-09-20 09:19:20 -03:00
builtin-data.c perf debug: Remove needless include directives from debug.h 2019-08-31 19:10:19 -03:00
builtin-diff.c perf diff: Use llabs() with 64-bit values 2019-11-28 08:08:38 -03:00
builtin-evlist.c perf evsel: Introduce evsel_fprintf.h 2019-09-25 16:26:34 -03:00
builtin-ftrace.c perf auxtrace: Uninline functions that touch perf_session 2019-08-31 22:24:10 -03:00
builtin-help.c perf debug: Remove needless include directives from debug.h 2019-08-31 19:10:19 -03:00
builtin-inject.c perf inject: Cut AUX area samples 2019-11-22 10:48:13 -03:00
builtin-kallsyms.c perf dsos: Move the dsos struct and its methods to separate source files 2019-08-31 22:24:10 -03:00
builtin-kmem.c perf callchain: Use 'struct map_symbol' in 'struct callchain_cursor_node' 2019-11-12 08:20:53 -03:00
builtin-kvm.c perf kvm: Use evlist layer api when possible 2019-11-06 15:43:05 -03:00
builtin-list.c perf list: Hide deprecated events by default 2019-10-19 15:35:01 -03:00
builtin-lock.c perf session: Return error code for perf_session__new() function on failure 2019-09-20 15:58:11 -03:00
builtin-mem.c perf session: Return error code for perf_session__new() function on failure 2019-09-20 15:58:11 -03:00
builtin-probe.c perf probe: No need for symbol.h, symbol_conf is enough 2019-08-31 22:24:10 -03:00
builtin-record.c perf record: Add support for AUX area sampling 2019-11-22 10:48:13 -03:00
builtin-report.c perf thread: Rename thread->mg to thread->maps 2019-11-26 11:07:46 -03:00
builtin-sched.c perf callchain: Use 'struct map_symbol' in 'struct callchain_cursor_node' 2019-11-12 08:20:53 -03:00
builtin-script.c perf script: Move map__fprintf_srccode() to near its only user 2019-11-26 11:07:45 -03:00
builtin-stat.c perf parse: Report initial event parsing error 2019-11-18 19:14:29 -03:00
builtin-timechart.c perf session: Return error code for perf_session__new() function on failure 2019-09-20 15:58:11 -03:00
builtin-top.c perf annotate: Pass a 'map_symbol' in places receiving a pair of 'map' and 'symbol' pointers 2019-11-12 08:20:53 -03:00
builtin-trace.c perf parse: Report initial event parsing error 2019-11-18 19:14:29 -03:00
builtin-version.c perf symbols: Move mem_info and branch_info out of symbol.h 2019-08-31 22:27:48 -03:00
builtin.h
check-headers.sh Merge branch 'x86/core' into perf/core, to resolve conflicts and to pick up completed topic tree 2019-11-25 09:09:27 +01:00
command-list.txt
CREDITS
design.txt
Makefile
Makefile.config perf tools: Allow to link with libbpf dynamicaly 2019-11-26 11:17:45 -03:00
Makefile.perf perf tools: Allow to link with libbpf dynamicaly 2019-11-26 11:17:45 -03:00
MANIFEST
perf-archive.sh
perf-completion.sh
perf-read-vdso.c
perf-sys.h perf tools: Make usage of test_attr__* optional for perf-sys.h 2019-10-31 21:38:41 +01:00
perf-with-kcore.sh
perf.c libperf: Merge libperf_set_print() into libperf_init() 2019-09-25 09:51:49 -03:00
perf.h perf time-utils: Adopt rdclock() from perf.h 2019-08-29 17:38:32 -03:00