Messages in this thread | | | Date | Fri, 29 Feb 2008 16:55:30 -0800 | From | Randy Dunlap <> | Subject | Re: [patch 6/6] mempolicy: update NUMA memory policy documentation |
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David Rientjes wrote: > Updates Documentation/vm/numa_memory_policy.txt and > Documentation/filesystems/tmpfs.txt to describe optional mempolicy mode > flags. > > Cc: Christoph Lameter <clameter@sgi.com> > Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> > Cc: Andi Kleen <ak@suse.de> > Cc: Randy Dunlap <randy.dunlap@oracle.com> > Signed-off-by: David Rientjes <rientjes@google.com> > Signed-off-by: Paul Jackson <pj@sgi.com> > --- > Documentation/filesystems/tmpfs.txt | 12 +++ > Documentation/vm/numa_memory_policy.txt | 131 +++++++++++++++++++++++------- > 2 files changed, 112 insertions(+), 31 deletions(-) > > diff --git a/Documentation/vm/numa_memory_policy.txt b/Documentation/vm/numa_memory_policy.txt > --- a/Documentation/vm/numa_memory_policy.txt > +++ b/Documentation/vm/numa_memory_policy.txt
> @@ -231,6 +234,80 @@ Components of Memory Policies > the temporary interleaved system default policy works in this > mode. > > + Linux memory policy supports the following optional mode flag:
flags:
> + > + MPOL_F_STATIC_NODES: This flag specifies that the nodemask passed by > + the user should not be remapped if the task or VMA's set of allowed > + nodes changes after the memory policy has been defined. > + > + Without this flag, anytime a mempolicy is rebound because of a > + change in the set of allowed nodes, the node (Preferred) or > + nodemask (Bind, Interleave) is remapped to the new set of > + allowed nodes. This may result in nodes being used that were > + previously undesired. > + > + With this flag, if the user specified nodes overlap with the
user-specified
> + nodes allowed by the task's cpuset, then the memory policy is > + applied to their intersection. If the two sets of nodes do not > + overlap, the Default policy is used. > + > + For example, consider a task that is attached to a cpuset with > + mems 1-3 that sets an Interleave policy over the same set. If > + the cpuset's mems change to 3-5, the Interleave will now occur > + over nodes 3, 4, and 5. With this flag, however, since only node > + 3 is allowed from the user's nodemask, the "interleave" only > + occurs over that node. If no nodes from the user's nodemask are > + now allowed, the Default behavior is used. > + > + MPOL_F_STATIC_NODES cannot be used with MPOL_F_RELATIVE_NODES. > +
-- ~Randy
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