diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2014-04-17 19:39:10 +0200 |
|---|---|---|
| committer | Jiri Olsa <jolsa@kernel.org> | 2014-06-12 16:53:19 +0200 |
| commit | 0c4e774fad0202b91dea8d99c04e9bdf2c2c6647 (patch) | |
| tree | 9a94e5f06914e70d8093e43ea4f85f0843aaba1c /tools/perf/util/perf_regs.c | |
| parent | 17314e2385c6627fcab4b8f97bd6668bb63495c0 (diff) | |
perf tools: Cache register accesses for unwind processing
Caching registers value into an array. Got about 4% speed up
of perf_reg_value function for report command processing
dwarf unwind stacks.
Output from report over 1.5 GB data with DWARF unwind stacks:
(TODO fix perf diff)
current code:
5.84% perf perf [.] perf_reg_value
change:
1.94% perf perf [.] perf_reg_value
And little bit of overall speed up:
(perf stat -r 5 -e '{cycles,instructions}:u' ...)
current code:
310,298,611,754 cycles ( +- 0.33% )
439,669,689,341 instructions ( +- 0.03% )
188.656753166 seconds time elapsed ( +- 0.82% )
change:
291,315,329,878 cycles ( +- 0.22% )
391,763,485,304 instructions ( +- 0.03% )
180.742249687 seconds time elapsed ( +- 0.64% )
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/1401892622-30848-2-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Diffstat (limited to 'tools/perf/util/perf_regs.c')
| -rw-r--r-- | tools/perf/util/perf_regs.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/tools/perf/util/perf_regs.c b/tools/perf/util/perf_regs.c index a3539ef30b15..43168fb0d9a2 100644 --- a/tools/perf/util/perf_regs.c +++ b/tools/perf/util/perf_regs.c @@ -1,11 +1,15 @@ #include <errno.h> #include "perf_regs.h" +#include "event.h" int perf_reg_value(u64 *valp, struct regs_dump *regs, int id) { int i, idx = 0; u64 mask = regs->mask; + if (regs->cache_mask & (1 << id)) + goto out; + if (!(mask & (1 << id))) return -EINVAL; @@ -14,6 +18,10 @@ int perf_reg_value(u64 *valp, struct regs_dump *regs, int id) idx++; } - *valp = regs->regs[idx]; + regs->cache_mask |= (1 << id); + regs->cache_regs[id] = regs->regs[idx]; + +out: + *valp = regs->cache_regs[id]; return 0; } |