summaryrefslogtreecommitdiff
path: root/tools/perf/util/unwind-libunwind.c
diff options
context:
space:
mode:
authorJiri Olsa <jolsa@kernel.org>2014-04-30 17:47:27 +0400
committerJiri Olsa <jolsa@kernel.org>2014-06-12 18:53:20 +0400
commitc658045197814b7d762662f9aa9f652379121a03 (patch)
tree4f61850960139bbf9382480c32a4247f8a907ab1 /tools/perf/util/unwind-libunwind.c
parentbda6ee4a94d1e1be0c1428d37bc0d3da2e5793ad (diff)
downloadlinux-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.c2
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;