Messages in this thread | | | Date | Fri, 9 Nov 2007 09:26:01 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: [PATCH 6/6] Use one zonelist that is filtered by nodemask |
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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.
What happens though if an MPOL_BIND policy is in effect? The node used must then be the nearest node from the policy mask....
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