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 contains a slight difference (~0.01% in terms of
number of lines printed) on callchains which were not resolved.
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Jean Pihet <jean.pi...@linaro.org>
Cc: Arun Sharma <asha...@fb.com>
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/util/thread.c | 3 +++
tools/perf/util/unwind-libunwind.c | 9 +++++++++
tools/perf/util/unwind.h | 3 +++
3 files changed, 15 insertions(+)
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index c1fa4a3597ea..e67d4ca6de44 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -119,6 +119,9 @@ 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;
diff --git a/tools/perf/util/unwind-libunwind.c
b/tools/perf/util/unwind-libunwind.c
index 76ec25663c95..6df06f0cd177 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -535,11 +535,20 @@ 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;
+
+ 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;
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index 4b99c6280c2a..d68f24d4f01b 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -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)
@@ -30,6 +31,7 @@ static inline int unwind__prepare_access(struct thread
*thread)
return 0;
}
+static inline void unwind__flush_access(struct thread *thread) {}
static inline void unwind__finish_access(struct thread *thread) {}
#endif
#else
@@ -49,6 +51,7 @@ static inline int unwind__prepare_access(struct thread
*thread)
return 0;
}
+static inline void unwind__flush_access(struct thread *thread) {}
static inline void unwind__finish_access(struct thread *thread) {}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
#endif /* __UNWIND_H */
--
2.1.0
--
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