Messages in this thread |  | | | Date | Wed, 4 May 2011 12:17:22 -0700 (PDT) | | From | David Rientjes <> | | Subject | Re: [PATCH] Allocate memory cgroup structures in local nodes |
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On Wed, 4 May 2011, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com> > > [Andrew: since this is a regression and a very simple fix > could you still consider it for .39? Thanks] >
Before that's considered, the order of the arguments to alloc_pages_exact_node() needs to be fixed.
> dde79e005a769 added a regression that the memory cgroup data structures > all end up in node 0 because the first attempt at allocating them > would not pass in a node hint. Since the initialization runs on CPU #0 > it would all end up node 0. This is a problem on large memory systems, > where node 0 would lose a lot of memory. > > Change the alloc_pages_exact to alloc_pages_exact_node. This will > still fall back to other nodes if not enough memory is available. >
The vmalloc_node() calls ensure that the nid is actually set in N_HIGH_MEMORY and fails otherwise (we don't fallback to using vmalloc()), so it looks like the failures for alloc_pages_exact_node() and vmalloc_node() would be different? Why do we want to fallback for one and not the other?
> [RED-PEN: right now it would fall back first before trying > vmalloc_node. Probably not the best strategy ... But I left it like > that for now.] > > Reported-by: Doug Nelson > CC: Michal Hocko <mhocko@suse.cz> > Cc: Dave Hansen <dave@linux.vnet.ibm.com> > Cc: Balbir Singh <balbir@in.ibm.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Signed-off-by: Andi Kleen <ak@linux.intel.com> > --- > mm/page_cgroup.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c > index 9905501..1f4e20f 100644 > --- a/mm/page_cgroup.c > +++ b/mm/page_cgroup.c > @@ -134,7 +134,7 @@ static void *__init_refok alloc_page_cgroup(size_t size, int nid) > { > void *addr = NULL; > > - addr = alloc_pages_exact(size, GFP_KERNEL | __GFP_NOWARN); > + addr = alloc_pages_exact_node(nid, size, GFP_KERNEL | __GFP_NOWARN); > if (addr) > return addr; >
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