diff options
| author |   Andi Kleen <ak@linux.intel.com> | 2019-11-20 16:15:11 -0800 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-28 08:08:38 -0300 |
| commit | d96645821e940bddff3fc5290656f83bf70d4c92 (patch) | |
| tree | 879409141d525cc6996d212afcfe5c01fe6d77be /tools/perf/util/srccode.c | |
| parent | perf regs: Make perf_reg_name() return "unknown" instead of NULL (diff) | |
| download | linux-dev-d96645821e940bddff3fc5290656f83bf70d4c92.tar.xz linux-dev-d96645821e940bddff3fc5290656f83bf70d4c92.zip | |
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>
Diffstat (limited to 'tools/perf/util/srccode.c')
| -rw-r--r-- | tools/perf/util/srccode.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/tools/perf/util/srccode.c b/tools/perf/util/srccode.c index d84ed8b6caaa..c29edaaca863 100644 --- a/tools/perf/util/srccode.c +++ b/tools/perf/util/srccode.c @@ -16,6 +16,7 @@ #include "srccode.h" #include "debug.h" #include <internal/lib.h> // page_size +#include "fncache.h" #define MAXSRCCACHE (32*1024*1024) #define MAXSRCFILES 64 @@ -36,14 +37,6 @@ static LIST_HEAD(srcfile_list); static long map_total_sz; static int num_srcfiles; -static unsigned shash(unsigned char *s) -{ - unsigned h = 0; - while (*s) - h = 65599 * h + *s++; - return h ^ (h >> 16); -} - static int countlines(char *map, int maplen) { int numl; |