Commit d0775264 authored Aug 07, 2012 by Frederic Weisbecker Committed by Arnaldo Carvalho de Melo Aug 10, 2012

perf: Add attribute to filter out callchains



Introducing following bits to the the perf_event_attr struct:

  - exclude_callchain_kernel to filter out kernel callchain
    from the sample dump

  - exclude_callchain_user to filter out user callchain
    from the sample dump

We need to be able to disable standard user callchain dump when we use
the dwarf cfi callchain mode, because frame pointer based user
callchains are useless in this mode.

Implementing also exclude_callchain_kernel to have complete set of
options.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
[ Added kernel callchains filtering ]
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Arun Sharma <asharma@fb.com>
Cc: Benjamin Redelings <benjamin.redelings@nescent.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Ulrich Drepper <drepper@gmail.com>
Link: http://lkml.kernel.org/r/1344345647-11536-7-git-send-email-jolsa@redhat.com


Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent c5ebcedb

include/linux/perf_event.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -268,7 +268,10 @@ struct perf_event_attr {
		exclude_host : 1, /* don't count in host */
		exclude_guest : 1, /* don't count in guest */

		__reserved_1 : 43;
		exclude_callchain_kernel : 1, /* exclude kernel callchains */
		exclude_callchain_user : 1, /* exclude user callchains */

		__reserved_1 : 41;

		union {
		__u32 wakeup_events; /* wakeup every n events */

kernel/events/callchain.c

+24 −14

Original line number	Diff line number	Diff line
		@@ -159,6 +159,11 @@ perf_callchain(struct perf_event event, struct pt_regs regs)
		int rctx;
		struct perf_callchain_entry *entry;

		int kernel = !event->attr.exclude_callchain_kernel;
		int user = !event->attr.exclude_callchain_user;

		if (!kernel && !user)
		return NULL;

		entry = get_callchain_entry(&rctx);
		if (rctx == -1)
		@@ -169,9 +174,13 @@ perf_callchain(struct perf_event event, struct pt_regs regs)

		entry->nr = 0;

		if (!user_mode(regs)) {
		if (kernel && !user_mode(regs)) {
		perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
		perf_callchain_kernel(entry, regs);
		}

		if (user) {
		if (!user_mode(regs)) {
		if (current->mm)
		regs = task_pt_regs(current);
		else
		@@ -188,6 +197,7 @@ perf_callchain(struct perf_event event, struct pt_regs regs)
		perf_callchain_store(entry, PERF_CONTEXT_USER);
		perf_callchain_user(entry, regs);
		}
		}

		exit_put:
		put_callchain_entry(rctx);

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