Re: [2.6.24 regression][BUGFIX] numactl --interleave=all doesn't works on memoryless node.

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Hi Lee-san

Unfortunately, 2.6.24-mm1 can't boot on fujitsu machine.
(hmm, origin.patch cause regression to pci initialization ;-)

instead, I tested 2.6.24 + your patch.
it seem work good :)

Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

and, I have a bit comment.


>  /* Do sanity checking on a policy */
> -static int mpol_check_policy(int mode, nodemask_t *nodes)
> +static int mpol_check_policy(int mode, nodemask_t *nodes, int was_empty)

was_empty argument is a bit ugly.
Could we unify mpol_check_policy and contextualize_policy?
mpol_check_policy only called from contextualize_policy.

> - 	return nodes_subset(*nodes, node_states[N_HIGH_MEMORY]) ? 0 : -EINVAL;
> + 	return 0;

Could we N_POSSIBLE check?

I attached the patch for my idea explain.
on my test environment, your patch and mine works good both.

- kosaki


---
 mm/mempolicy.c |   47 +++++++++++++++++++++--------------------------
 1 file changed, 21 insertions(+), 26 deletions(-)

Index: b/mm/mempolicy.c
===================================================================
--- a/mm/mempolicy.c	2008-02-07 17:19:09.000000000 +0900
+++ b/mm/mempolicy.c	2008-02-07 17:24:28.000000000 +0900
@@ -114,9 +114,25 @@ static void mpol_rebind_policy(struct me
                                const nodemask_t *newmask);
 
 /* Do sanity checking on a policy */
-static int mpol_check_policy(int mode, nodemask_t *nodes, int was_empty)
+static int mpol_check_policy(int mode, nodemask_t *nodes)
 {
-	int is_empty = nodes_empty(*nodes);
+	int was_empty;
+	int is_empty;
+
+	if (!nodes)
+		return 0;
+
+	/*
+	 * Remember whether in coming nodemask was empty,  If not,
+	 * restrict the nodes to the allowed nodes in the cpuset.
+	 * This is guaranteed to be a subset of nodes with memory.
+	 */
+	cpuset_update_task_memory_state();
+	was_empty = nodes_empty(*nodes);
+	if (!was_empty)
+		nodes_and(*nodes, *nodes, cpuset_current_mems_allowed);
+
+	is_empty = nodes_empty(*nodes);
 
 	switch (mode) {
 	case MPOL_DEFAULT:
@@ -144,7 +160,7 @@ static int mpol_check_policy(int mode, n
 			return -EINVAL;
 		break;
 	}
- 	return 0;
+ 	return nodes_subset(*nodes, node_states[N_POSSIBLE]) ? 0 : -EINVAL;
 }
 
 /* Generate a custom zonelist for the BIND policy. */
@@ -432,27 +448,6 @@ static int mbind_range(struct vm_area_st
 	return err;
 }
 
-static int contextualize_policy(int mode, nodemask_t *nodes)
-{
-	int was_empty;
-
-	if (!nodes)
-		return 0;
-
-	/*
-	 * Remember whether in coming nodemask was empty,  If not,
-	 * restrict the nodes to the allowed nodes in the cpuset.
-	 * This is guaranteed to be a subset of nodes with memory.
-	 */
-	cpuset_update_task_memory_state();
-	was_empty = nodes_empty(*nodes);
-	if (!was_empty)
-		nodes_and(*nodes, *nodes, cpuset_current_mems_allowed);
-
-	return mpol_check_policy(mode, nodes, was_empty);
-}
-
-
 /*
  * Update task->flags PF_MEMPOLICY bit: set iff non-default
  * mempolicy.  Allows more rapid checking of this (combined perhaps
@@ -488,7 +483,7 @@ static long do_set_mempolicy(int mode, n
 {
 	struct mempolicy *new;
 
-	if (contextualize_policy(mode, nodes))
+	if (mpol_check_policy(mode, nodes))
 		return -EINVAL;
 	new = mpol_new(mode, nodes);
 	if (IS_ERR(new))
@@ -817,7 +812,7 @@ static long do_mbind(unsigned long start
 	if (end == start)
 		return 0;
 
-	if (contextualize_policy(mode, nmask))
+	if (mpol_check_policy(mode, nmask))
 		return -EINVAL;
 
 	new = mpol_new(mode, nmask);