perf evsel: Introduce mmap support

Out of the code in 'perf top'. Record is next in line.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 5 insertions, 66 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 15d89bede2f..7d723ad0bfa 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1095,43 +1095,12 @@ static void event__process_sample(const event_t *self,
         }
 }
 
-struct mmap_data {
-        void                    *base;
-        int                     mask;
-        unsigned int            prev;
-};
-
-static int perf_evsel__alloc_mmap_per_thread(struct perf_evsel *evsel,
-                                             int ncpus, int nthreads)
-{
-        evsel->priv = xyarray__new(ncpus, nthreads, sizeof(struct mmap_data));
-        return evsel->priv != NULL ? 0 : -ENOMEM;
-}
-
-static void perf_evsel__free_mmap(struct perf_evsel *evsel)
-{
-        xyarray__delete(evsel->priv);
-        evsel->priv = NULL;
-}
-
-static unsigned int mmap_read_head(struct mmap_data *md)
-{
-        struct perf_event_mmap_page *pc = md->base;
-        int head;
-
-        head = pc->data_head;
-        rmb();
-
-        return head;
-}
-
 static void perf_session__mmap_read_counter(struct perf_session *self,
                                             struct perf_evsel *evsel,
                                             int cpu, int thread_idx)
 {
-        struct xyarray *mmap_array = evsel->priv;
-        struct mmap_data *md = xyarray__entry(mmap_array, cpu, thread_idx);
-        unsigned int head = mmap_read_head(md);
+        struct perf_mmap *md = xyarray__entry(evsel->mmap, cpu, thread_idx);
+        unsigned int head = perf_mmap__read_head(md);
         unsigned int old = md->prev;
         unsigned char *data = md->base + page_size;
         struct sample_data sample;
@@ -1210,35 +1179,9 @@ static void perf_session__mmap_read(struct perf_session *self)
         }
 }
 
-static void start_counter(int i, struct perf_evlist *evlist,
-                          struct perf_evsel *evsel)
-{
-        struct xyarray *mmap_array = evsel->priv;
-        struct mmap_data *mm;
-        int thread_index;
-
-        for (thread_index = 0; thread_index < threads->nr; thread_index++) {
-                assert(FD(evsel, i, thread_index) >= 0);
-                fcntl(FD(evsel, i, thread_index), F_SETFL, O_NONBLOCK);
-
-                evlist->pollfd[evlist->nr_fds].fd = FD(evsel, i, thread_index);
-                evlist->pollfd[evlist->nr_fds].events = POLLIN;
-                evlist->nr_fds++;
-
-                mm = xyarray__entry(mmap_array, i, thread_index);
-                mm->prev = 0;
-                mm->mask = mmap_pages*page_size - 1;
-                mm->base = mmap(NULL, (mmap_pages+1)*page_size,
-                                PROT_READ, MAP_SHARED, FD(evsel, i, thread_index), 0);
-                if (mm->base == MAP_FAILED)
-                        die("failed to mmap with %d (%s)\n", errno, strerror(errno));
-        }
-}
-
 static void start_counters(struct perf_evlist *evlist)
 {
         struct perf_evsel *counter;
-        int i;
 
         list_for_each_entry(counter, &evlist->entries, node) {
                 struct perf_event_attr *attr = &counter->attr;
@@ -1282,11 +1225,9 @@ try_again:
                         die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
                         exit(-1);
                 }
-        }
 
-        for (i = 0; i < cpus->nr; i++) {
-                list_for_each_entry(counter, &evlist->entries, node)
-                        start_counter(i, evsel_list, counter);
+                if (perf_evsel__mmap(counter, cpus, threads, mmap_pages, evlist) < 0)
+                        die("failed to mmap with %d (%s)\n", errno, strerror(errno));
         }
 }
 
@@ -1453,7 +1394,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
                 usage_with_options(top_usage, options);
 
         list_for_each_entry(pos, &evsel_list->entries, node) {
-                if (perf_evsel__alloc_mmap_per_thread(pos, cpus->nr, threads->nr) < 0 ||
+                if (perf_evsel__alloc_mmap(pos, cpus->nr, threads->nr) < 0 ||
                     perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
                         goto out_free_fd;
                 /*
@@ -1485,8 +1426,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 
         status = __cmd_top();
 out_free_fd:
-        list_for_each_entry(pos, &evsel_list->entries, node)
-                perf_evsel__free_mmap(pos);
         perf_evlist__delete(evsel_list);
 
         return status;