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authorLee Schermerhorn <Lee.Schermerhorn@hp.com>2007-10-16 10:24:51 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 18:42:54 +0200
commit754af6f5a85fcd1ecb456851d20c65e4c6ce10ab (patch)
tree8c985bfd704a8c993d6ca992725969c6fc5c9e5a /mm/mempolicy.c
parentmm: prevent kswapd from freeing excessive amounts of lowmem (diff)
downloadlinux-754af6f5a85fcd1ecb456851d20c65e4c6ce10ab.tar.xz
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Mem Policy: add MPOL_F_MEMS_ALLOWED get_mempolicy() flag
Allow an application to query the memories allowed by its context. Updated numa_memory_policy.txt to mention that applications can use this to obtain allowed memories for constructing valid policies. TODO: update out-of-tree libnuma wrapper[s], or maybe add a new wrapper--e.g., numa_get_mems_allowed() ? Also, update numa syscall man pages. Tested with memtoy V>=0.13. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--mm/mempolicy.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3a45b7dd0a09..ccbdb22147bb 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -526,8 +526,18 @@ long do_get_mempolicy(int *policy, nodemask_t *nmask,
struct mempolicy *pol = current->mempolicy;
cpuset_update_task_memory_state();
- if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR))
+ if (flags &
+ ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
return -EINVAL;
+
+ if (flags & MPOL_F_MEMS_ALLOWED) {
+ if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
+ return -EINVAL;
+ *policy = 0; /* just so it's initialized */
+ *nmask = cpuset_current_mems_allowed;
+ return 0;
+ }
+
if (flags & MPOL_F_ADDR) {
down_read(&mm->mmap_sem);
vma = find_vma_intersection(mm, addr, addr+1);