On Wed, Jun 24, 2015 at 05:50:28PM -0500, Nathan Zimmer wrote: > From e18aa6158a60c2134b4eef93c856f3b5b250b122 Mon Sep 17 00:00:00 2001 > From: Nathan Zimmer <nzim...@sgi.com> > Date: Thu, 11 Jun 2015 10:47:39 -0500 > Subject: [RFC] Avoid the contention in set_cpus_allowed > > Noticing some scaling issues at larger box sizes (64 nodes+) I found that in > some > cases we are spending significant amounts of time in set_cpus_allowed_ptr. > > My assumption is that it is getting stuck on migration. > So if we create the thread on the target node and restrict cpus before we > start > the thread then we don't have to suffer migration. > > Cc: Mel Gorman <mgor...@suse.de> > Cc: Waiman Long <waiman.l...@hp.com > Cc: Dave Hansen <dave.han...@intel.com> > Cc: Scott Norton <scott.nor...@hp.com> > Cc: Daniel J Blueman <dan...@numascale.com> > Signed-off-by: Nathan Zimmer <nzim...@sgi.com> >
I asked yesterday if set_cpus_allowed_ptr() was required and I made a mistake because it is. The node parameter for kthread_create_on_node() controls where it gets created but not how it is scheduled after that. Sorry for the noise. The patch makes sense to me now, lets see if it helps Daniel. -- Mel Gorman SUSE Labs -- 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/
