Messages in this thread | | | Date | Mon, 15 Jun 2009 16:25:43 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH 0/3] Fix malloc() stall in zone_reclaim() and bring behaviour more in line with expectations V3 |
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On Mon, Jun 15, 2009 at 11:01:41AM -0400, Christoph Lameter wrote: > On Mon, 15 Jun 2009, Mel Gorman wrote: > > > > May I ask your worry? > > > > > > > Simply that I believe the intention of PF_SWAPWRITE here was to allow > > zone_reclaim() to aggressively reclaim memory if the reclaim_mode allowed > > it as it was a statement that off-node accesses are really not desired. > > Right. > > > Ok. I am not fully convinced but I'll not block it either if believe it's > > necessary. My current understanding is that this patch only makes a difference > > if the server is IO congested in which case the system is struggling anyway > > and an off-node access is going to be relatively small penalty overall. > > Conceivably, having PF_SWAPWRITE set makes things worse in that situation > > and the patch makes some sense. > > We could drop support for RECLAIM_SWAP if that simplifies things. >
I don't think that is necessary. While I expect it's very rarely used, I imagine a situation where it would be desirable on a system that had large amounts of tmpfs pages but where it wasn't critical they remain in-memory.
Removing PF_SWAPWRITE would make it less aggressive and if you were happy with that, then that would be good enough for me.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab
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