On Thu, 2014-01-23 at 11:31 -0800, Nicholas A. Bellinger wrote: > On Thu, 2014-01-23 at 20:12 +0100, Peter Zijlstra wrote: > > On Thu, Jan 23, 2014 at 10:40:04AM -0800, Nicholas A. Bellinger wrote: > > > On Wed, 2014-01-22 at 11:53 -0800, Nicholas A. Bellinger wrote: > > > > Hi Peter, > > > > > > > > Does this satisfy your questions..? > > > > > > > > Do you have any more concerns about TASK_RUNNING + prepare_to_wait() > > > > usage in percpu_ida_alloc() that need to be addressed before I can drop > > > > this series into target-pending/for-next to address the original bug..? > > > > > > > > > > Given the silence, > > > > You mean the silence in which I send a 4+ emails earlier today? > > > > > I'll assume your OK with the initial TASK_RUNNING + > > > prepare_to_wait() bit, right..? > > > > No, I would prefer not to do that. While it does work its awkward at > > best. > > AFAICT, those changes don't address the original bug that the series was > trying to address, allowing the percpu_ida_alloc() tag stealing slow > path to be interrupted by a signal.. > > Also, keep in mind this change needs to be backported to >= v3.12, which > is why the percpu_ida changes have been kept to a minimum. > <A little too eager to SEND> So would you prefer the following addition to the original bugfix instead..? diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index a48ce2e..58b6714 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -174,7 +174,8 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state) * * global lock held and irqs disabled, don't need percpu lock */ - prepare_to_wait(&pool->wait, &wait, state); + if (state != TASK_RUNNING) + prepare_to_wait(&pool->wait, &wait, state); if (!tags->nr_free) alloc_global_tags(pool, tags); @@ -199,8 +200,9 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state) local_irq_save(flags); tags = this_cpu_ptr(pool->tag_cpu); } + if (state != TASK_RUNNING) + finish_wait(&pool->wait, &wait); - finish_wait(&pool->wait, &wait); return tag; } EXPORT_SYMBOL_GPL(percpu_ida_alloc); -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html