On 07/25/2013 11:31 PM, Tejun Heo wrote: > Hello, Lai. > > On Thu, Jul 25, 2013 at 06:52:02PM +0800, Lai Jiangshan wrote: >> The unbound pools and their workers can be destroyed/cleared >> when their refcnt become zero. But the cpu pool can't be destroyed >> due to they are always referenced, their refcnt are always > 0. >> >> We don't want to destroy the cpu pools, but we want to destroy >> the workers of the pool when the pool is full idle after the cpu >> is offline. This is the default behavior in old days until >> we removed the trustee_thread(). >> >> We need to find a new way to restore this behavior, >> We add offline_pool() and POOL_OFFLINE flag to do so. > > Hmmm... if I'm not confused, now the cpu pools just behave like a > normal unbound pool when the cpu goes down,
cpu pools are always referenced, they don't behave like unbound pool. > which means that the idle > cpu workers will exit once idle timeout is reached, right? No, no code to force the cpu workers quit currently. you can just offline a cpu to see what happened to the workers. > I really > don't think it'd be worthwhile to add extra logic to accelerate the > process. > > Note that there actually are benefits to doing it asynchronously as > CPUs go up and down very frequently on mobile platforms and destroying > idle workers as soon as possible would just mean that we'd be doing a > lot of work which isn't necessary. I mean, we even grew an explicit > mechanism to park kthreads to avoid repeatedly creating and destroying > per-cpu kthreads as cpus go up and down. I don't see any point in > adding code to go the other direction. > > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
