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Commit d20031bb authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Add AUX area tracing Snapshot Mode 



Add support for making snapshots of AUX area tracing data.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-9-git-send-email-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0ad21f68

tools/perf/perf.h

+3 −0
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ struct record_opts { 
	bool	     sample_intr_regs;

	bool	     running_time;

	bool	     full_auxtrace;

	bool	     auxtrace_snapshot_mode;

	unsigned int freq;

	unsigned int mmap_pages;

	unsigned int auxtrace_mmap_pages;
@@ -62,6 +63,8 @@ struct record_opts { 
	u64          branch_stack;

	u64	     default_interval;

	u64	     user_interval;

	size_t	     auxtrace_snapshot_size;

	const char   *auxtrace_snapshot_opts;

	bool	     sample_transaction;

	unsigned     initial_delay;

	bool         use_clockid;

tools/perf/util/auxtrace.c

+75 −10
Original line number Diff line number Diff line
@@ -504,6 +504,29 @@ void auxtrace_record__free(struct auxtrace_record *itr) 
		itr->free(itr);

}



int auxtrace_record__snapshot_start(struct auxtrace_record *itr)

{

	if (itr && itr->snapshot_start)

		return itr->snapshot_start(itr);

	return 0;

}



int auxtrace_record__snapshot_finish(struct auxtrace_record *itr)

{

	if (itr && itr->snapshot_finish)

		return itr->snapshot_finish(itr);

	return 0;

}



int auxtrace_record__find_snapshot(struct auxtrace_record *itr, int idx,

				   struct auxtrace_mmap *mm,

				   unsigned char *data, u64 *head, u64 *old)

{

	if (itr && itr->find_snapshot)

		return itr->find_snapshot(itr, idx, mm, data, head, old);

	return 0;

}



int auxtrace_record__options(struct auxtrace_record *itr,

			     struct perf_evlist *evlist,

			     struct record_opts *opts)
@@ -520,6 +543,19 @@ u64 auxtrace_record__reference(struct auxtrace_record *itr) 
	return 0;

}



int auxtrace_parse_snapshot_options(struct auxtrace_record *itr,

				    struct record_opts *opts, const char *str)

{

	if (!str)

		return 0;



	if (itr)

		return itr->parse_snapshot_options(itr, opts, str);



	pr_err("No AUX area tracing to snapshot\n");

	return -EINVAL;

}



struct auxtrace_record *__weak

auxtrace_record__init(struct perf_evlist *evlist __maybe_unused, int *err)

{
@@ -1077,16 +1113,26 @@ int perf_event__process_auxtrace_error(struct perf_tool *tool __maybe_unused, 
	return 0;

}



int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr,

			struct perf_tool *tool, process_auxtrace_t fn)

static int __auxtrace_mmap__read(struct auxtrace_mmap *mm,

				 struct auxtrace_record *itr,

				 struct perf_tool *tool, process_auxtrace_t fn,

				 bool snapshot, size_t snapshot_size)

{

	u64 head = auxtrace_mmap__read_head(mm);

	u64 old = mm->prev, offset, ref;

	u64 head, old = mm->prev, offset, ref;

	unsigned char *data = mm->base;

	size_t size, head_off, old_off, len1, len2, padding;

	union perf_event ev;

	void *data1, *data2;



	if (snapshot) {

		head = auxtrace_mmap__read_snapshot_head(mm);

		if (auxtrace_record__find_snapshot(itr, mm->idx, mm, data,

						   &head, &old))

			return -1;

	} else {

		head = auxtrace_mmap__read_head(mm);

	}



	if (old == head)

		return 0;
@@ -1106,6 +1152,9 @@ int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr, 
	else

		size = mm->len - (old_off - head_off);



	if (snapshot && size > snapshot_size)

		size = snapshot_size;



	ref = auxtrace_record__reference(itr);



	if (head > old || size <= head || mm->mask) {
@@ -1153,6 +1202,7 @@ int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr, 


	mm->prev = head;



	if (!snapshot) {

		auxtrace_mmap__write_tail(mm, head);

		if (itr->read_finish) {

			int err;
@@ -1161,10 +1211,25 @@ int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr, 
			if (err < 0)

				return err;

		}

	}



	return 1;

}



int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr,

			struct perf_tool *tool, process_auxtrace_t fn)

{

	return __auxtrace_mmap__read(mm, itr, tool, fn, false, 0);

}



int auxtrace_mmap__read_snapshot(struct auxtrace_mmap *mm,

				 struct auxtrace_record *itr,

				 struct perf_tool *tool, process_auxtrace_t fn,

				 size_t snapshot_size)

{

	return __auxtrace_mmap__read(mm, itr, tool, fn, true, snapshot_size);

}



/**

 * struct auxtrace_cache - hash table to implement a cache

 * @hashtable: the hashtable

tools/perf/util/auxtrace.h

+41 −0
Original line number Diff line number Diff line
@@ -276,6 +276,10 @@ struct auxtrace_mmap_params { 
 * @info_priv_size: return the size of the private data in auxtrace_info_event

 * @info_fill: fill-in the private data in auxtrace_info_event

 * @free: free this auxtrace record structure

 * @snapshot_start: starting a snapshot

 * @snapshot_finish: finishing a snapshot

 * @find_snapshot: find data to snapshot within auxtrace mmap

 * @parse_snapshot_options: parse snapshot options

 * @reference: provide a 64-bit reference number for auxtrace_event

 * @read_finish: called after reading from an auxtrace mmap

 */
@@ -289,12 +293,36 @@ struct auxtrace_record { 
			 struct auxtrace_info_event *auxtrace_info,

			 size_t priv_size);

	void (*free)(struct auxtrace_record *itr);

	int (*snapshot_start)(struct auxtrace_record *itr);

	int (*snapshot_finish)(struct auxtrace_record *itr);

	int (*find_snapshot)(struct auxtrace_record *itr, int idx,

			     struct auxtrace_mmap *mm, unsigned char *data,

			     u64 *head, u64 *old);

	int (*parse_snapshot_options)(struct auxtrace_record *itr,

				      struct record_opts *opts,

				      const char *str);

	u64 (*reference)(struct auxtrace_record *itr);

	int (*read_finish)(struct auxtrace_record *itr, int idx);

};



#ifdef HAVE_AUXTRACE_SUPPORT



/*

 * In snapshot mode the mmapped page is read-only which makes using

 * __sync_val_compare_and_swap() problematic.  However, snapshot mode expects

 * the buffer is not updated while the snapshot is made (e.g. Intel PT disables

 * the event) so there is not a race anyway.

 */

static inline u64 auxtrace_mmap__read_snapshot_head(struct auxtrace_mmap *mm)

{

	struct perf_event_mmap_page *pc = mm->userpg;

	u64 head = ACCESS_ONCE(pc->aux_head);



	/* Ensure all reads are done after we read the head */

	rmb();

	return head;

}



static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm)

{

	struct perf_event_mmap_page *pc = mm->userpg;
@@ -346,6 +374,11 @@ typedef int (*process_auxtrace_t)(struct perf_tool *tool, 
int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr,

			struct perf_tool *tool, process_auxtrace_t fn);



int auxtrace_mmap__read_snapshot(struct auxtrace_mmap *mm,

				 struct auxtrace_record *itr,

				 struct perf_tool *tool, process_auxtrace_t fn,

				 size_t snapshot_size);



int auxtrace_queues__init(struct auxtrace_queues *queues);

int auxtrace_queues__add_event(struct auxtrace_queues *queues,

			       struct perf_session *session,
@@ -383,6 +416,9 @@ void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key); 
struct auxtrace_record *auxtrace_record__init(struct perf_evlist *evlist,

					      int *err);



int auxtrace_parse_snapshot_options(struct auxtrace_record *itr,

				    struct record_opts *opts,

				    const char *str);

int auxtrace_record__options(struct auxtrace_record *itr,

			     struct perf_evlist *evlist,

			     struct record_opts *opts);
@@ -392,6 +428,11 @@ int auxtrace_record__info_fill(struct auxtrace_record *itr, 
			       struct auxtrace_info_event *auxtrace_info,

			       size_t priv_size);

void auxtrace_record__free(struct auxtrace_record *itr);

int auxtrace_record__snapshot_start(struct auxtrace_record *itr);

int auxtrace_record__snapshot_finish(struct auxtrace_record *itr);

int auxtrace_record__find_snapshot(struct auxtrace_record *itr, int idx,

				   struct auxtrace_mmap *mm,

				   unsigned char *data, u64 *head, u64 *old);

u64 auxtrace_record__reference(struct auxtrace_record *itr);



int auxtrace_index__auxtrace_event(struct list_head *head, union perf_event *event,