On Wed, Jun 02, 2010 at 01:59:43AM +1000, Nick Piggin wrote: > On Tue, Jun 01, 2010 at 05:48:10PM +0200, Andi Kleen wrote: > > Nick Piggin <npiggin@xxxxxxx> writes: > > > > > This isn't really a new problem, and I don't know how important it is, > > > but I recently came across it again when doing some aim7 testing with > > > huge numbers of tasks. > > > > Seems reasonable. Of course you need to at least > > save/restore the old CPU policy, and use a subset of it. > > The mpolicy? My patch does that (mpol_prefer_cpu_start/end). The real > problem is that it can actually violate the parent's mempolicy. For > example MPOL_BIND and cpus_allowed set on a node outside the mempolicy. I don't see where you store 'old', but maybe I missed it. > > slightly more difficult. The advantage would be that on multiple > > migrations it would follow. And it would be a bit slower for > > the initial case. > > Migrate what on touch? Talking mainly about kernel memory structures, > task_struct, mm, vmas, page tables, kernel stack, etc. Migrate task_struct, mm, vmas, page tables, kernel stack on reasonable touch. As long as they are not shared it shouldn't be too difficult. -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>