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mm/mpol: Make MPOL_LOCAL a real policy

tip:sched/numa tip-bot for Peter Zijlstra 1 participant 1 message May 18, 2012

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Commit-ID:  03ed7b538ca08b982be2d5893a696bdce573665c
Gitweb:     http://git.kernel.org/tip/03ed7b538ca08b982be2d5893a696bdce573665c
Author:     Peter Zijlstra <[email protected]>
AuthorDate: Mon, 19 Mar 2012 18:54:52 +0100
Committer:  Ingo Molnar <[email protected]>
CommitDate: Thu, 17 May 2012 14:06:13 +0200

mm/mpol: Make MPOL_LOCAL a real policy

Make MPOL_LOCAL a real and exposed policy such that applications that relied on the previous default behaviour can explicitly request it.

Requested-by Christoph Lameter <[email protected]>
Signed-off-by Peter Zijlstra <[email protected]>
Cc Suresh Siddha <[email protected]>
Cc Paul Turner <[email protected]>
Cc Dan Smith <[email protected]>
Cc Bharata B Rao <[email protected]>
Cc Lee Schermerhorn <[email protected]>
Cc Rik van Riel <[email protected]>
Cc Andrea Arcangeli <[email protected]>
Cc Andrew Morton <[email protected]>
Cc Linus Torvalds <[email protected]>
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Ingo Molnar <[email protected]>
---
 include/linux/mempolicy.h |    1 +
 mm/mempolicy.c            |    9 ++++++---
 2 files changed, 7 insertions(+), 3 deletions(-)
include/linux/mempolicy.h +1 -0
index 7c727a9..a51e5db 100644
@@ -20,6 +20,7 @@ enum {
 	MPOL_PREFERRED,
 	MPOL_BIND,
 	MPOL_INTERLEAVE,
+	MPOL_LOCAL,
 	MPOL_MAX,	/* always last member of enum */
 };
mm/mempolicy.c +6 -3
index 82d209b..a7516db 100644
@@ -269,6 +269,10 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
 			     (flags & MPOL_F_RELATIVE_NODES)))
 				return ERR_PTR(-EINVAL);
 		}
+	} else if (mode == MPOL_LOCAL) {
+		if (!nodes_empty(*nodes))
+			return ERR_PTR(-EINVAL);
+		mode = MPOL_PREFERRED;
 	} else if (nodes_empty(*nodes))
 		return ERR_PTR(-EINVAL);
 	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);

@@ -2260,7 +2264,6 @@ void numa_default_policy(void)
  * "local" is pseudo-policy:  MPOL_PREFERRED with MPOL_F_LOCAL flag
  * Used only for mpol_parse_str() and mpol_to_str()
  */
-#define MPOL_LOCAL MPOL_MAX
 static const char * const policy_modes[] =
 {
 	[MPOL_DEFAULT]    = "default",

@@ -2313,12 +2316,12 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
 	if (flags)
 		*flags++ = '\0';	/* terminate mode string */
 
-	for (mode = 0; mode <= MPOL_LOCAL; mode++) {
+	for (mode = 0; mode < MPOL_MAX; mode++) {
 		if (!strcmp(str, policy_modes[mode])) {
 			break;
 		}
 	}
-	if (mode > MPOL_LOCAL)
+	if (mode >= MPOL_MAX)
 		goto out;
 
 	switch (mode) {