The patch titled
mempolicy: fixup Fallback for Default Shmem Policy
has been added to the -mm tree. Its filename is
mempolicy-fixup-fallback-for-default-shmem-policy.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mempolicy: fixup Fallback for Default Shmem Policy
From: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
get_vma_policy() is not handling fallback to task policy correctly when the
get_policy() vm_op returns NULL. The NULL overwrites the 'pol' variable that
was holding the fallback task mempolicy. So, it was falling back directly to
system default policy.
Fix get_vma_policy() to use only non-NULL policy returned from the vma
get_policy op.
shm_get_policy() was falling back to current task's mempolicy if the "backing
file system" [tmpfs vs hugetlbfs] does not support the get_policy vm_op and
the vma policy is null. This is incorrect for show_numa_maps() which is
likely querying the numa_maps of some task other than current. Remove this
fallback.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/shm.c | 3 +--
mm/mempolicy.c | 7 +++++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff -puN ipc/shm.c~mempolicy-fixup-fallback-for-default-shmem-policy ipc/shm.c
--- a/ipc/shm.c~mempolicy-fixup-fallback-for-default-shmem-policy
+++ a/ipc/shm.c
@@ -274,8 +274,7 @@ static struct mempolicy *shm_get_policy(
else if (vma->vm_policy) {
pol = vma->vm_policy;
mpol_get(pol); /* get_vma_policy() expects this */
- } else
- pol = current->mempolicy;
+ }
return pol;
}
#endif
diff -puN mm/mempolicy.c~mempolicy-fixup-fallback-for-default-shmem-policy mm/mempolicy.c
--- a/mm/mempolicy.c~mempolicy-fixup-fallback-for-default-shmem-policy
+++ a/mm/mempolicy.c
@@ -1262,7 +1262,7 @@ asmlinkage long compat_sys_mbind(compat_
* @task != current]. It is the caller's responsibility to
* free the reference in these cases.
*/
-static struct mempolicy * get_vma_policy(struct task_struct *task,
+static struct mempolicy *get_vma_policy(struct task_struct *task,
struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = task->mempolicy;
@@ -1270,7 +1270,10 @@ static struct mempolicy * get_vma_policy
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy) {
- pol = vma->vm_ops->get_policy(vma, addr);
+ struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
+ addr);
+ if (vpol)
+ pol = vpol;
shared_pol = 1; /* if pol non-NULL, add ref below */
} else if (vma->vm_policy &&
vma->vm_policy->policy != MPOL_DEFAULT)
_
Patches currently in -mm which might be from lee.schermerhorn@xxxxxx are
mm-use-zonelists-instead-of-zones-when-direct-reclaiming-pages.patch
mm-introduce-node_zonelist-for-accessing-the-zonelist-for-a-gfp-mask.patch
mm-remember-what-the-preferred-zone-is-for-zone_statistics.patch
mm-use-two-zonelist-that-are-filtered-by-gfp-mask.patch
mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx.patch
mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx-fix-memcg-ooms.patch
mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx-just-return-do_try_to_free_pages.patch
mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx-just-return-do_try_to_free_pages-do_try_to_free_pages-gfp_mask-redundant.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-doc-fixes.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-make-dequeue_huge_page_vma-obey-mpol_bind-nodemask.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-make-dequeue_huge_page_vma-obey-mpol_bind-nodemask-rework.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-deporkify.patch
mempolicy-add-bitmap_onto-and-bitmap_fold-operations.patch
mempolicy-create-mempolicy_operations-structure-fix.patch
mempolicy-disallow-static-or-relative-flags-for-local-preferred-mode.patch
mempolicy-fix-parsing-of-tmpfs-mpol-mount-option.patch
mempolicy-rename-mpol_free-to-mpol_put.patch
mempolicy-rename-mpol_copy-to-mpol_dup.patch
mempolicy-write-lock-mmap_sem-while-changing-task-mempolicy.patch
mempolicy-fixup-fallback-for-default-shmem-policy.patch
mempolicy-rename-struct-mempolicy-policy-member-to-mode.patch
mempolicy-mark-shared-policies-for-unref.patch
mempolicy-document-setget_policy-vm_ops-apis.patch
mempolicy-rework-mempolicy-reference-counting.patch
mempolicy-use-mpol_preferred-for-system-wide-default-policy.patch
mempolicy-mpol_preferred-cleanups-for-local-allocation.patch
mempolicy-use-mpol_f_local-to-indicate-preferred-local-policy.patch
mempolicy-clean-up-mpol-to-str-mempolicy-formatting.patch
mempolicy-rework-shmem-mpol-parsing-and-display.patch
mempolicy-support-mpol=local-tmpfs-mount-option.patch
mempolicy-use-struct-mempolicy-pointer-in-shmem_sb_info.patch
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