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| author | Jiri Olsa <jolsa@kernel.org> | 2014-04-30 17:47:27 +0400 |
|---|---|---|
| committer | Jiri Olsa <jolsa@kernel.org> | 2014-06-12 18:53:20 +0400 |
| commit | c658045197814b7d762662f9aa9f652379121a03 (patch) | |
| tree | 4f61850960139bbf9382480c32a4247f8a907ab1 /tools/perf/util/unwind-libunwind.c | |
| parent | bda6ee4a94d1e1be0c1428d37bc0d3da2e5793ad (diff) | |
| download | linux-c658045197814b7d762662f9aa9f652379121a03.tar.xz | |
perf tools: Cache dso data file descriptor
Caching dso data file descriptors to avoid expensive re-opens
especially during DWARF unwind.
We keep dsos data file descriptors open until their count reaches
the half of the current fd open limit (RLIMIT_NOFILE). In this case
we close file descriptor of the first opened dso object.
We've got overall speedup (~27% for my workload) of report:
'perf report --stdio -i perf-test.data' (3 runs)
(perf-test.data size was around 12GB)
current code:
545,640,944,228 cycles ( +- 0.53% )
785,255,798,320 instructions ( +- 0.03% )
366.340910010 seconds time elapsed ( +- 3.65% )
after change:
435,895,036,114 cycles ( +- 0.26% )
636,790,271,176 instructions ( +- 0.04% )
266.481463387 seconds time elapsed ( +- 0.13% )
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1401892622-30848-7-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Diffstat (limited to 'tools/perf/util/unwind-libunwind.c')
| -rw-r--r-- | tools/perf/util/unwind-libunwind.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index 4f8dd9ee3899..25578b98f5c5 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -250,7 +250,6 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, /* Check the .eh_frame section for unwinding info */ offset = elf_section_offset(fd, ".eh_frame_hdr"); - dso__data_close(dso); if (offset) ret = unwind_spec_ehframe(dso, machine, offset, @@ -271,7 +270,6 @@ static int read_unwind_spec_debug_frame(struct dso *dso, /* Check the .debug_frame section for unwinding info */ *offset = elf_section_offset(fd, ".debug_frame"); - dso__data_close(dso); if (*offset) return 0; |