perf: Convert perf header attrs into attr events

Bypasses the attr perf header code and replaces it with a
synthesized event and processing function that accomplishes the
same thing, used when reading/writing perf data to/from a pipe.

Making the attrs into events allows them to be streamed over a
pipe along with the rest of the header data (in later patches).
It also paves the way to allowing events to be added and removed
from perf sessions dynamically.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-6-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 79 insertions, 0 deletions

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 8d05337d1a59..e36173934e8b 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -807,3 +807,82 @@ perf_header__find_attr(u64 id, struct perf_header *header)
 
         return NULL;
 }
+
+int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
+                           event__handler_t process,
+                           struct perf_session *session)
+{
+        event_t *ev;
+        size_t size;
+        int err;
+
+        size = sizeof(struct perf_event_attr);
+        size = ALIGN(size, sizeof(u64));
+        size += sizeof(struct perf_event_header);
+        size += ids * sizeof(u64);
+
+        ev = malloc(size);
+
+        ev->attr.attr = *attr;
+        memcpy(ev->attr.id, id, ids * sizeof(u64));
+
+        ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
+        ev->attr.header.size = size;
+
+        err = process(ev, session);
+
+        free(ev);
+
+        return err;
+}
+
+int event__synthesize_attrs(struct perf_header *self,
+                            event__handler_t process,
+                            struct perf_session *session)
+{
+        struct perf_header_attr *attr;
+        int i, err = 0;
+
+        for (i = 0; i < self->attrs; i++) {
+                attr = self->attr[i];
+
+                err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
+                                             process, session);
+                if (err) {
+                        pr_debug("failed to create perf header attribute\n");
+                        return err;
+                }
+        }
+
+        return err;
+}
+
+int event__process_attr(event_t *self, struct perf_session *session)
+{
+        struct perf_header_attr *attr;
+        unsigned int i, ids, n_ids;
+
+        attr = perf_header_attr__new(&self->attr.attr);
+        if (attr == NULL)
+                return -ENOMEM;
+
+        ids = self->header.size;
+        ids -= (void *)&self->attr.id - (void *)self;
+        n_ids = ids / sizeof(u64);
+
+        for (i = 0; i < n_ids; i++) {
+                if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
+                        perf_header_attr__delete(attr);
+                        return -ENOMEM;
+                }
+        }
+
+        if (perf_header__add_attr(&session->header, attr) < 0) {
+                perf_header_attr__delete(attr);
+                return -ENOMEM;
+        }
+
+        perf_session__update_sample_type(session);
+
+        return 0;
+}