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authorRobin Holt <holt@sgi.com>2006-01-15 00:20:48 +0300
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-15 05:27:07 +0300
commit7339ff8302fd70aabf5f1ae26e0c4905fa74a495 (patch)
tree38ee561d51b7e4db7c0d6dd9ebd9fc22c2b6ab88 /mm/mempolicy.c
parent852cf918dcf2ae46468b425e679fbcbf0ea8fdbb (diff)
downloadlinux-7339ff8302fd70aabf5f1ae26e0c4905fa74a495.tar.xz
[PATCH] Add tmpfs options for memory placement policies
Anything that writes into a tmpfs filesystem is liable to disproportionately decrease the available memory on a particular node. Since there's no telling what sort of application (e.g. dd/cp/cat) might be dropping large files there, this lets the admin choose the appropriate default behavior for their site's situation. Introduce a tmpfs mount option which allows specifying a memory policy and a second option to specify the nodelist for that policy. With the default policy, tmpfs will behave as it does today. This patch adds support for preferred, bind, and interleave policies. The default policy will cause pages to be added to tmpfs files on the node which is doing the writing. Some jobs expect a single process to create and manage the tmpfs files. This results in a node which has a significantly reduced number of free pages. With this patch, the administrator can specify the policy and nodes for that policy where they would prefer allocations. This patch was originally written by Brent Casavant and Hugh Dickins. I added support for the bind and preferred policies and the mpol_nodelist mount option. Signed-off-by: Brent Casavant <bcasavan@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b62cab575a84..3171f884d245 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1359,6 +1359,30 @@ restart:
return 0;
}
+void mpol_shared_policy_init(struct shared_policy *info, int policy,
+ nodemask_t *policy_nodes)
+{
+ info->root = RB_ROOT;
+ spin_lock_init(&info->lock);
+
+ if (policy != MPOL_DEFAULT) {
+ struct mempolicy *newpol;
+
+ /* Falls back to MPOL_DEFAULT on any error */
+ newpol = mpol_new(policy, policy_nodes);
+ if (!IS_ERR(newpol)) {
+ /* Create pseudo-vma that contains just the policy */
+ struct vm_area_struct pvma;
+
+ memset(&pvma, 0, sizeof(struct vm_area_struct));
+ /* Policy covers entire file */
+ pvma.vm_end = TASK_SIZE;
+ mpol_set_shared_policy(info, &pvma, newpol);
+ mpol_free(newpol);
+ }
+ }
+}
+
int mpol_set_shared_policy(struct shared_policy *info,
struct vm_area_struct *vma, struct mempolicy *npol)
{