perf symbols: Kill struct build_id_list and die() another day

No need for this struct and its allocations, we can just use the
->build_id member we already have in struct dso, then ask for it
to be read, and later traverse the dsos list, writing the
buildid table to the perf.data file.

As a bonus, one more die() function got killed.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1258582853-8579-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 28 insertions, 49 deletions

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 1f771ce3a957..34c6fcb82d92 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -69,13 +69,6 @@ struct build_id_event {
         char                     filename[];
 };
 
-struct build_id_list {
-        struct build_id_event   event;
-        struct list_head        list;
-        const char              *dso_name;
-        int                     len;
-};
-
 typedef union event_union {
         struct perf_event_header        header;
         struct ip_event                 ip;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index b01a9537977f..31731f1606b2 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -176,18 +176,24 @@ static int do_write(int fd, const void *buf, size_t size)
         return 0;
 }
 
-static int write_buildid_table(int fd, struct list_head *id_head)
+static int dsos__write_buildid_table(int fd)
 {
-        struct build_id_list *iter, *next;
-
-        list_for_each_entry_safe(iter, next, id_head, list) {
-                struct build_id_event *b = &iter->event;
-
-                if (do_write(fd, b, sizeof(*b)) < 0 ||
-                    do_write(fd, iter->dso_name, iter->len) < 0)
+        struct dso *pos;
+
+        list_for_each_entry(pos, &dsos, node) {
+                struct build_id_event b;
+                size_t len;
+
+                if (!pos->has_build_id)
+                        continue;
+                len = pos->long_name_len + 1;
+                len = ALIGN(len, 64);
+                memset(&b, 0, sizeof(b));
+                memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
+                b.header.size = sizeof(b) + len;
+                if (do_write(fd, &b, sizeof(b)) < 0 ||
+                    do_write(fd, pos->long_name, len) < 0)
                         return -1;
-                list_del(&iter->list);
-                free(iter);
         }
 
         return 0;
@@ -196,14 +202,13 @@ static int write_buildid_table(int fd, struct list_head *id_head)
 static void
 perf_header__adds_write(struct perf_header *self, int fd)
 {
-        LIST_HEAD(id_list);
         int nr_sections;
         struct perf_file_section *feat_sec;
         int sec_size;
         u64 sec_start;
         int idx = 0;
 
-        if (fetch_build_id_table(&id_list))
+        if (dsos__read_build_ids())
                 perf_header__set_feat(self, HEADER_BUILD_ID);
 
         nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
@@ -238,7 +243,7 @@ perf_header__adds_write(struct perf_header *self, int fd)
 
                 /* Write build-ids */
                 buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
-                if (write_buildid_table(fd, &id_list) < 0)
+                if (dsos__write_buildid_table(fd) < 0)
                         die("failed to write buildid table");
                 buildid_sec->size = lseek(fd, 0, SEEK_CUR) - buildid_sec->offset;
         }
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 594f36a1da8f..946ec319568b 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -883,38 +883,19 @@ out_close:
         return err;
 }
 
-bool fetch_build_id_table(struct list_head *head)
+bool dsos__read_build_ids(void)
 {
-        bool have_buildid = false;
+        bool have_build_id = false;
         struct dso *pos;
 
-        list_for_each_entry(pos, &dsos, node) {
-                struct build_id_list *new;
-                struct build_id_event b;
-                size_t len;
-
-                if (filename__read_build_id(pos->long_name,
-                                            &b.build_id,
-                                            sizeof(b.build_id)) < 0)
-                        continue;
-                have_buildid = true;
-                memset(&b.header, 0, sizeof(b.header));
-                len = pos->long_name_len + 1;
-                len = ALIGN(len, 64);
-                b.header.size = sizeof(b) + len;
-
-                new = malloc(sizeof(*new));
-                if (!new)
-                        die("No memory\n");
-
-                memcpy(&new->event, &b, sizeof(b));
-                new->dso_name = pos->long_name;
-                new->len = len;
-
-                list_add_tail(&new->list, head);
-        }
+        list_for_each_entry(pos, &dsos, node)
+                if (filename__read_build_id(pos->long_name, pos->build_id,
+                                            sizeof(pos->build_id)) > 0) {
+                        have_build_id     = true;
+                        pos->has_build_id = true;
+                }
 
-        return have_buildid;
+        return have_build_id;
 }
 
 int filename__read_build_id(const char *filename, void *bf, size_t size)
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 5ad1019607dd..546eb766d81e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -89,7 +89,7 @@ char dso__symtab_origin(const struct dso *self);
 void dso__set_build_id(struct dso *self, void *build_id);
 
 int filename__read_build_id(const char *filename, void *bf, size_t size);
-bool fetch_build_id_table(struct list_head *head);
+bool dsos__read_build_ids(void);
 int build_id__sprintf(u8 *self, int len, char *bf);
 
 int load_kernel(symbol_filter_t filter);