Commit 380b5143 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf callchain: Use global caching provided by libunwind 



The libunwind provides two caching policy which are global and
per-thread.  As perf unwinds callchains in a single thread, it'd
sufficient to use global caching.

This speeds up my perf report from 14s to 7s on a ~260MB data file.
Although the output sometimes contains a slight difference (~0.01% in
terms of number of lines printed) on callchains which were not resolved.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarJean Pihet <jean.pihet@linaro.org>
Cc: Arun Sharma <asharma@fb.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: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1412556363-26229-4-git-send-email-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1776b106

tools/perf/util/thread.c

+3 −0
Original line number Diff line number Diff line
@@ -117,6 +117,9 @@ int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, 
		if (!new)

			return -ENOMEM;

		list_add(&new->list, &thread->comm_list);



		if (exec)

			unwind__flush_access(thread);

	}



	thread->comm_set = true;

tools/perf/util/unwind-libunwind.c

+12 −0
Original line number Diff line number Diff line
@@ -539,11 +539,23 @@ int unwind__prepare_access(struct thread *thread) 
		return -ENOMEM;

	}



	unw_set_caching_policy(addr_space, UNW_CACHE_GLOBAL);

	thread__set_priv(thread, addr_space);



	return 0;

}



void unwind__flush_access(struct thread *thread)

{

	unw_addr_space_t addr_space;



	if (callchain_param.record_mode != CALLCHAIN_DWARF)

		return;



	addr_space = thread__priv(thread);

	unw_flush_cache(addr_space, 0, 0);

}



void unwind__finish_access(struct thread *thread)

{

	unw_addr_space_t addr_space;

tools/perf/util/unwind.h

+3 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, 
#ifdef HAVE_LIBUNWIND_SUPPORT

int libunwind__arch_reg_id(int regnum);

int unwind__prepare_access(struct thread *thread);

void unwind__flush_access(struct thread *thread);

void unwind__finish_access(struct thread *thread);

#else

static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
@@ -30,6 +31,7 @@ static inline int unwind__prepare_access(struct thread *thread __maybe_unused) 
	return 0;

}



static inline void unwind__flush_access(struct thread *thread __maybe_unused) {}

static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}

#endif

#else
@@ -49,6 +51,7 @@ static inline int unwind__prepare_access(struct thread *thread __maybe_unused) 
	return 0;

}



static inline void unwind__flush_access(struct thread *thread __maybe_unused) {}

static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}

#endif /* HAVE_DWARF_UNWIND_SUPPORT */

#endif /* __UNWIND_H */

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