On Thu, Jul 01, 2010 at 02:55:07PM +0300, Michael S. Tsirkin wrote: > On Thu, Jul 01, 2010 at 01:43:23PM +0200, Peter Zijlstra wrote: > > On Thu, 2010-07-01 at 13:19 +0200, Peter Zijlstra wrote: > > > On Thu, 2010-07-01 at 14:07 +0300, Michael S. Tsirkin wrote: > > > > Author: Sridhar Samudrala <sri@xxxxxxxxxx> > > > > > > > > sched: export sched_set/getaffinity to modules > > > > > > > > vhost-net driver wants to copy the affinity from the > > > > owner thread to thread it creates. Export > > > > sched_set/get affinity to modules to make this possible > > > > when vhost is built as a module. > > > > > Urgh,.. so why again is that a good idea? > > > > In particular: > > - who sets the affinity of the task? > > management tools do this when they start qemu. > > > - why can't it set the kernel thread's affinity too? > > It can. However: the threads are started internally by the driver > when qemu does an ioctl. What we want to do is give it a sensible > default affinity. management tool can later tweak it if it wants to. > > > - what happens if someone changes the tasks' affinity? > > We would normally create a cgroup including all internal > tasks, making it easy to find and change affinity for > them all if necessary. > > > So no, I don't think this is a sensible thing to do at all. The patch using this is here: http://www.mail-archive.com/kvm@xxxxxxxxxxxxxxx/msg35411.html It simply copies the affinity from the parent when thread is created. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
