Messages in this thread | | | Date | Wed, 1 Aug 2007 02:23:13 +0200 | From | Nick Piggin <> | Subject | Re: [rfc] balance-on-fork NUMA placement |
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On Tue, Jul 31, 2007 at 11:14:08AM +0200, Andi Kleen wrote: > On Tuesday 31 July 2007 07:41, Nick Piggin wrote: > > > I haven't given this idea testing yet, but I just wanted to get some > > opinions on it first. NUMA placement still isn't ideal (eg. tasks with > > a memory policy will not do any placement, and process migrations of > > course will leave the memory behind...), but it does give a bit more > > chance for the memory controllers and interconnects to get evenly > > loaded. > > I didn't think slab honored mempolicies by default? > At least you seem to need to set special process flags. > > > NUMA balance-on-fork code is in a good position to allocate all of a new > > process's memory on a chosen node. However, it really only starts > > allocating on the correct node after the process starts running. > > > > task and thread structures, stack, mm_struct, vmas, page tables etc. are > > all allocated on the parent's node. > > The page tables should be only allocated when the process runs; except > for the PGD.
We certainly used to copy all page tables on fork. Not any more, but we must still copy anonymous page tables. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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