perf tools: Cache register accesses for unwind processing (0c4e774f) · Commits · 戴 / test

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>

tools/perf/util/event.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -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 {

tools/perf/util/perf_regs.c

+9 −1

Original line number	Diff line number	Diff line
		#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;
		}

tools/perf/util/perf_regs.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -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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