From 0c4e774fad0202b91dea8d99c04e9bdf2c2c6647 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 17 Apr 2014 19:39:10 +0200 Subject: [PATCH] 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 Cc: Arnaldo Carvalho de Melo Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jean Pihet Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1401892622-30848-2-git-send-email-jolsa@kernel.org Signed-off-by: Jiri Olsa --- 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 9ba2eb3bdcfd..e5dd40addb30 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; @@ -89,6 +90,10 @@ 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 a3539ef30b15..43168fb0d9a2 100644 --- a/tools/perf/util/perf_regs.c +++ b/tools/perf/util/perf_regs.c @@ -1,11 +1,15 @@ #include #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 79c78f74e0cf..980dbf76bc98 100644 --- a/tools/perf/util/perf_regs.h +++ b/tools/perf/util/perf_regs.h @@ -2,7 +2,8 @@ #define __PERF_REGS_H #include -#include "event.h" + +struct regs_dump; #ifdef HAVE_PERF_REGS_SUPPORT #include @@ -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) { -- 2.20.1