Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 01/13] perf tools: Cache register accesses for unwind processing | Date | Mon, 2 Jun 2014 23:18:35 +0200 |
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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% )
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> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/perf/util/event.h | 5 +++++ tools/perf/util/perf_regs.c | 10 +++++++++- tools/perf/util/perf_regs.h | 4 +++- 3 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h index d970232..d369ad9 100644 --- a/tools/perf/util/event.h +++ b/tools/perf/util/event.h @@ -7,6 +7,7 @@ #include "../perf.h" #include "map.h" #include "build-id.h" +#include "perf_regs.h" struct mmap_event { struct perf_event_header header; @@ -87,6 +88,10 @@ struct regs_dump { u64 abi; u64 mask; u64 *regs; + + /* Cached values/mask filled by first register access. */ + u64 cache_regs[PERF_REGS_MAX]; + u64 cache_mask; }; struct stack_dump { diff --git a/tools/perf/util/perf_regs.c b/tools/perf/util/perf_regs.c index a3539ef..43168fb 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; } diff --git a/tools/perf/util/perf_regs.h b/tools/perf/util/perf_regs.h index 79c78f7..980dbf7 100644 --- a/tools/perf/util/perf_regs.h +++ b/tools/perf/util/perf_regs.h @@ -2,7 +2,8 @@ #define __PERF_REGS_H #include <linux/types.h> -#include "event.h" + +struct regs_dump; #ifdef HAVE_PERF_REGS_SUPPORT #include <perf_regs.h> @@ -11,6 +12,7 @@ int perf_reg_value(u64 *valp, struct regs_dump *regs, int id); #else #define PERF_REGS_MASK 0 +#define PERF_REGS_MAX 0 static inline const char *perf_reg_name(int id __maybe_unused) { -- 1.8.3.1
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