On 10/16/2013 11:01 PM, David Ahern wrote:
On 10/16/13 1:59 PM, Waiman Long wrote:
This patch adds a new --max-stack option to perf-report to limit the
depth of callchain stack data to look at to reduce the time it takes
for perf-report to finish its processing. It trades the presence of
trailing stack information with faster speed.
I like the patch. I have a similar option in my perf-sched-timehist
command, and I have a patch somewhere for perf-script.
It would be even better to pass this arg kernel side and limit the
stack depth at data collection time.
That will require option a similar option on the record side. However,
the overhead of collecting more stack ip address isn't as high as that
in the report side.
---8<---
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 72eae74..d90d04a 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -37,6 +37,12 @@
#include <linux/bitmap.h>
+/*
+ * 2-level stringification macro to enable stringification of macro
value
+ * */
+#define __to_string(x) #x
+#define STRINGIFY(x) __to_string(x)
These 2 lines should be somewhere else -- like util/util.h
I will move that to a common header file.
---8<---
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 2122141..2725aca 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -771,7 +771,8 @@ static void perf_event__process_sample(struct
perf_tool *tool,
sample->callchain) {
err = machine__resolve_callchain(machine, evsel,
al.thread, sample,
- &parent, &al);
+ &parent, &al,
+ PERF_MAX_STACK_DEPTH);
if (err)
return;
}
Why not add the option to perf-top as well? copy-paste.
I had thought about it, but I decided to wait for feedback before doing
it. I will make that change in the next version.
-Longman
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
