Commit-ID: 0c4e774fad0202b91dea8d99c04e9bdf2c2c6647
Gitweb: http://git.kernel.org/tip/0c4e774fad0202b91dea8d99c04e9bdf2c2c6647
Author: Jiri Olsa <jo...@kernel.org>
AuthorDate: Thu, 17 Apr 2014 19:39:10 +0200
Committer: Jiri Olsa <jo...@kernel.org>
CommitDate: Thu, 12 Jun 2014 16:53:19 +0200
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 <namhy...@kernel.org>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Jean Pihet <jean.pi...@linaro.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Link:
http://lkml.kernel.org/r/1401892622-30848-2-git-send-email-jo...@kernel.org
Signed-off-by: Jiri Olsa <jo...@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 9ba2eb3..e5dd40a 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 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)
{
--
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