Messages in this thread | | | Date | Fri, 9 Nov 2007 10:20:59 -0800 | From | Nishanth Aravamudan <> | Subject | Re: [PATCH 6/6] Use one zonelist that is filtered by nodemask |
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On 09.11.2007 [10:16:07 -0800], Nishanth Aravamudan wrote: > On 09.11.2007 [09:26:01 -0800], Christoph Lameter wrote: > > On Fri, 9 Nov 2007, Lee Schermerhorn wrote: > > > > > > On the other hand, if we call alloc_pages() with GFP_THISNODE set, there > > > > is no nid to base the allocation on, so we "fallback" to numa_node_id() > > > > [ almost like the nid had been specified as -1 ]. > > > > > > > > So I guess this is logical -- but I wonder, do we have any callers of > > > > alloc_pages(GFP_THISNODE) ? It seems like an odd thing to do, when > > > > alloc_pages_node() exists? > > > > > > I don't know if we have any current callers that do this, but absent any > > > documentation specifying otherwise, Mel's implementation matches what > > > I'd expect the behavior to be if I DID call alloc_pages with 'THISNODE. > > > However, we could specify that THISNODE is ignored in __alloc_pages() > > > and recommend the use of alloc_pages_node() passing numa_node_id() as > > > the nid parameter to achieve the behavior. This would eliminate the > > > check for 'THISNODE in __alloc_pages(). Just mask it off before calling > > > down to __alloc_pages_internal(). > > > > > > Does this make sense? > > > > I like consistency. If someone absolutely wants a local page then > > specifying GFP_THISNODE to __alloc_pages is okay. Leave as is I guess. > > Fair enough. > > > What happens though if an MPOL_BIND policy is in effect? The node used > > must then be the nearest node from the policy mask.... > > Indeed, this probably needs to be validated... Sigh, more interleaving > of policies and everything else...
Hrm, more importantly, isn't this an existing issue? Maybe should be resolved separately from the one zonelist patches.
-Nish
-- Nishanth Aravamudan <nacc@us.ibm.com> IBM Linux Technology Center - 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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