Messages in this thread | | | Date | Fri, 30 May 2014 18:43:45 -0300 | From | Marcelo Tosatti <> | Subject | Re: [PATCH] page_alloc: skip cpuset enforcement for lower zone allocations (v4) |
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On Fri, May 30, 2014 at 08:48:41AM -0500, Christoph Lameter wrote: > On Thu, 29 May 2014, Andrew Morton wrote: > > > > > > > if (!nodemask && gfp_zone(gfp_mask) < policy_zone) > > > nodemask = &node_states[N_ONLINE]; > > > > OK, thanks, I made the patch go away for now. > > > > And another issue is that the policy_zone may be highmem on 32 bit > platforms which will result in ZONE_NORMAL to be exempted. > > policy zone can actually even be ZONE_DMA for some platforms. The > check would not be useful at all on those. > > Ignoring the containing cpuset only makes sense for GFP_DMA32 on > 64 bit platforms and for GFP_DMA on platforms where there is an actual > difference in the address spaces supported by GFP_DMA (such as x86). > > Generally I think this is only useful for platforms that attempt to > support legacy devices only able to DMA to a portion of the memory address > space and that at the same time support NUMA for large address spaces. > This is a contradiction on the one hand this is a high end system and on > the other hand it attempts to support crippled DMA devices?
OK we will handle this in userspace.
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