Em Fri, Mar 14, 2014 at 03:00:06PM +0100, Jiri Olsa escreveu:
> Sharing map groups within all process threads. This way
> there's only one copy of mmap info and it's reachale
> from any thread within the process.
>
> Signed-off-by: Jiri Olsa <jo...@redhat.com>
> Cc: Don Zickus <dzic...@redhat.com>
> Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
> Cc: David Ahern <dsah...@gmail.com>
> Cc: Frederic Weisbecker <fweis...@gmail.com>
> Cc: Ingo Molnar <mi...@kernel.org>
> Cc: Namhyung Kim <namhy...@kernel.org>
> Cc: Paul Mackerras <pau...@samba.org>
> Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
> Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
> ---
> tools/perf/util/map.h | 2 ++
> tools/perf/util/thread.c | 37 ++++++++++++++++++++++++++++++++++---
> 2 files changed, 36 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
> index 99a6488..d4c8df2 100644
> --- a/tools/perf/util/map.h
> +++ b/tools/perf/util/map.h
> @@ -59,6 +59,8 @@ struct map_groups {
> struct rb_root maps[MAP__NR_TYPES];
> struct list_head removed_maps[MAP__NR_TYPES];
> struct machine *machine;
> + /* Used for thread sharing */
> + int refcnt;
So in the end you use those get/put ops for ref counting, cool. We need
some more of those for other stuff like those pointers in hist_entries
to dead_threads, etc.
- Arnaldo
> };
>
> static inline struct kmap *map__kmap(struct map *map)
> diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> index 7c1aad0..2599754 100644
> --- a/tools/perf/util/thread.c
> +++ b/tools/perf/util/thread.c
> @@ -156,6 +156,16 @@ int thread__fork(struct thread *thread, struct thread
> *parent, u64 timestamp)
> return 0;
> }
>
> +static struct thread* thread__get_leader(struct thread *thread)
> +{
> + pid_t pid = thread->pid_;
> +
> + if (pid == thread->tid)
> + return thread;
> +
> + return machine__findnew_thread(thread->machine, pid, pid);
> +}
> +
> static struct map_groups* thread__map_groups_alloc(struct thread *thread)
> {
> struct map_groups* mg = zalloc(sizeof(*mg));
> @@ -172,13 +182,34 @@ struct map_groups* thread__map_groups_get(struct thread
> *thread)
> {
> struct map_groups* mg = thread->mg;
>
> - if (!mg)
> - mg = thread__map_groups_alloc(thread);
> + if (!mg) {
> + struct thread *leader = thread__get_leader(thread);
> +
> + if (!leader)
> + return NULL;
> +
> + if (leader->mg)
> + mg = leader->mg;
> + else
> + mg = thread__map_groups_alloc(leader);
> +
> + if (leader != thread)
> + thread->mg = mg;
> +
> + mg->refcnt++;
> + }
>
> return mg;
> }
>
> void thread__map_groups_put(struct thread *thread)
> {
> - zfree(&thread->mg);
> + struct map_groups* mg = thread->mg;
> +
> + if (mg) {
> + BUG_ON(!mg->refcnt);
> +
> + if (!--mg->refcnt)
> + zfree(&thread->mg);
> + }
> }
> --
> 1.8.3.1
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