perf evlist: Extract perf_mmap__read() (0f4ccd11) · Commits · 戴 / test

tools/perf/util/evlist.c

+24 −15

Original line number	Diff line number	Diff line
		@@ -679,24 +679,15 @@ static struct perf_evsel perf_evlist__event2evsel(struct perf_evlist evlist,
		return NULL;
		}

		union perf_event perf_evlist__mmap_read(struct perf_evlist evlist, int idx)
		static union perf_event *
		perf_mmap__read(struct perf_mmap *md, bool overwrite, u64 head,
		u64 old, u64 *prev)
		{
		struct perf_mmap *md = &evlist->mmap[idx];
		u64 head;
		u64 old = md->prev;
		int diff;
		unsigned char *data = md->base + page_size;
		union perf_event *event = NULL;
		int diff = head - old;

		/*
		* Check if event was unmapped due to a POLLHUP/POLLERR.
		*/
		if (!atomic_read(&md->refcnt))
		return NULL;

		head = perf_mmap__read_head(md);
		diff = head - old;
		if (evlist->overwrite) {
		if (overwrite) {
		/*
		* If we're further behind than half the buffer, there's a chance
		* the writer will bite our tail and mess up the samples under us.
		@@ -751,11 +742,29 @@ union perf_event perf_evlist__mmap_read(struct perf_evlist evlist, int idx)
		}

		broken_event:
		md->prev = old;
		if (prev)
		*prev = old;

		return event;
		}

		union perf_event perf_evlist__mmap_read(struct perf_evlist evlist, int idx)
		{
		struct perf_mmap *md = &evlist->mmap[idx];
		u64 head;
		u64 old = md->prev;

		/*
		* Check if event was unmapped due to a POLLHUP/POLLERR.
		*/
		if (!atomic_read(&md->refcnt))
		return NULL;

		head = perf_mmap__read_head(md);

		return perf_mmap__read(md, evlist->overwrite, head, old, &md->prev);
		}

		static bool perf_mmap__empty(struct perf_mmap *md)
		{
		return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base;