On Wed, 27 Jun 2012 14:41:39 +0900 Minchan Kim <minchan@xxxxxxxxxx> wrote: > On 06/27/2012 02:12 PM, Andrew Morton wrote: > > > On Wed, 27 Jun 2012 11:09:31 +0900 Minchan Kim <minchan@xxxxxxxxxx> wrote: > > > >> On 06/27/2012 10:15 AM, Andrew Morton wrote: > >> > >>>> Considering mlock and CPU pinning > >>>>> of realtime thread is very rare, it might be rather expensive solution. > >>>>> Unfortunately, I have no idea better than you suggested. :( > >>>>> > >>>>> And looking 8891d6da17, mlock's lru_add_drain_all isn't must. > >>>>> If it's really bother us, couldn't we remove it? > >>> "grep lru_add_drain_all mm/*.c". They're all problematic. > >> > >> > >> Yeb but I'm not sure such system modeling is good. > >> Potentially, It could make problem once we use workqueue of other CPU. > > > > whut? > > > > My suggestion is that we switch lru_add_drain_all() to on_each_cpu() > > and delete schedule_on_each_cpu(). No workqueues. > > > Current problem is that RT thread doesn't yield his CPU so other tasks can't be scheduled in. > schedule_on_each_cpu uses system workqueue so if there are any user to try using > workqueue for the CPU(ex, schedule_work_on), he can make trouble, too. > So my question is I doubt such greedy RT thread modeling is good. > There's no way of fixing this without significantly degrading the service which rt priority offers. As we don't wish to degrade that service, schedule_work_on() and schedule_on_each_cpu() cannot be implemented reliably. So we delete them. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>