On Tue, 19 Dec 2006 03:43:19 +0300 Oleg Nesterov <[EMAIL PROTECTED]> wrote:
> On 12/18, Andrew Morton wrote: > > > > On Mon, 18 Dec 2006 01:34:16 +0300 > > Oleg Nesterov <[EMAIL PROTECTED]> wrote: > > > > > NOTE: I removed 'int cpu' parameter, flush_workqueue() locks/unlocks > > > workqueue_mutex unconditionally. It may be restored, but I think it > > > doesn't make much sense, we take the mutex for the very short time, > > > and the code becomes simpler. > > > > > > > Taking workqueue_mutex() unconditionally in flush_workqueue() means > > that we'll deadlock if a single-threaded workqueue callback handler calls > > flush_workqueue(). > > Well. But flush_workqueue() drops workqueue_mutex before going to sleep ? > > flush_workqueue(single_threaded_wq); > ... > mutex_lock(&workqueue_mutex); > ... > mutex_unlock(&workqueue_mutex); > wait_for_completition(); > handler runs, > calls flush_workqueue(), > workqueue_mutex is free Oh. OK. In that case we can switch to preempt_disable() for the cpu-hotplug holdoff. Sometime. > > It's an idiotic thing to do, but I think I spotted a site last week which > > does this. scsi? Not sure.. > > Ok, it is time to sleep. I'll look tomorrov and re-send if > flush_cpu_workqueue() > really needs "bool workqueue_mutex_is_locked" parameter. Hopefully not. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
