[PATCH 2.6.12-rc5 5/10] mm: manual page migration-rc3 -- sys_migrate_pages-mempolicy-migration-rc3.patch

[Ray Bryant <raybry@sgi.com>]

This patch adds code that translates the memory policy structures
as they are encountered so that they continue to represent where
memory should be allocated after the page migration has completed.

Signed-off-by: Ray Bryant <raybry@sgi.com>
--

 include/linux/mempolicy.h |    2 
 mm/mempolicy.c            |  116 ++++++++++++++++++++++++++++++++++++++++++++++
 mm/mmigrate.c             |   12 ++++
 3 files changed, 129 insertions(+), 1 deletion(-)

Index: linux-2.6.12-rc5-mhp1-page-migration-export/include/linux/mempolicy.h
===================================================================
--- linux-2.6.12-rc5-mhp1-page-migration-export.orig/include/linux/mempolicy.h	2005-06-13 11:12:34.000000000 -0700
+++ linux-2.6.12-rc5-mhp1-page-migration-export/include/linux/mempolicy.h	2005-06-13 11:12:51.000000000 -0700
@@ -152,6 +152,8 @@ struct mempolicy *mpol_shared_policy_loo
 
 extern void numa_default_policy(void);
 extern void numa_policy_init(void);
+extern int migrate_process_policy(struct task_struct *, unsigned int *);
+extern int migrate_vma_policy(struct vm_area_struct *, unsigned int *);
 
 #else
 
Index: linux-2.6.12-rc5-mhp1-page-migration-export/mm/mempolicy.c
===================================================================
--- linux-2.6.12-rc5-mhp1-page-migration-export.orig/mm/mempolicy.c	2005-06-13 11:12:34.000000000 -0700
+++ linux-2.6.12-rc5-mhp1-page-migration-export/mm/mempolicy.c	2005-06-13 11:12:51.000000000 -0700
@@ -1136,3 +1136,119 @@ void numa_default_policy(void)
 {
 	sys_set_mempolicy(MPOL_DEFAULT, NULL, 0);
 }
+
+/*
+ * update a node mask according to a migration request
+ */
+static void migrate_node_mask(unsigned long *new_node_mask,
+			      unsigned long *old_node_mask,
+			      unsigned int  *node_map)
+{
+	int i;
+
+	bitmap_zero(new_node_mask, MAX_NUMNODES);
+
+	i = find_first_bit(old_node_mask, MAX_NUMNODES);
+	while(i < MAX_NUMNODES) {
+		if (node_map[i] >= 0)
+			set_bit(node_map[i], new_node_mask);
+		else
+			set_bit(i, new_node_mask);
+		i = find_next_bit(old_node_mask, MAX_NUMNODES, i+1);
+	}
+}
+
+/*
+ * update a process or vma mempolicy according to a migration request
+ */
+static struct mempolicy *
+migrate_policy(struct mempolicy *old, unsigned int *node_map)
+{
+	struct mempolicy *new;
+	DECLARE_BITMAP(old_nodes, MAX_NUMNODES);
+	DECLARE_BITMAP(new_nodes, MAX_NUMNODES);
+	struct zone *z;
+	int i;
+
+	new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+	atomic_set(&new->refcnt, 0);
+	switch(old->policy) {
+	case MPOL_DEFAULT:
+		BUG();
+	case MPOL_INTERLEAVE:
+		migrate_node_mask(new->v.nodes, old->v.nodes, node_map);
+		break;
+	case MPOL_PREFERRED:
+		if (old->v.preferred_node>=0 &&
+			(node_map[old->v.preferred_node] >= 0))
+			new->v.preferred_node = node_map[old->v.preferred_node];
+		else
+			new->v.preferred_node = old->v.preferred_node;
+		break;
+	case MPOL_BIND:
+		bitmap_zero(old_nodes, MAX_NUMNODES);
+		for (i = 0; (z = old->v.zonelist->zones[i]) != NULL; i++)
+			set_bit(z->zone_pgdat->node_id, old_nodes);
+		migrate_node_mask(new_nodes, old_nodes, node_map);
+		new->v.zonelist = bind_zonelist(new_nodes);
+		if (!new->v.zonelist) {
+			kmem_cache_free(policy_cache, new);
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+	new->policy = old->policy;
+	return new;
+}
+
+/*
+ * update a process mempolicy based on a migration request
+ */
+int migrate_process_policy(struct task_struct *task, unsigned int  *node_map)
+{
+	struct mempolicy *new, *old = task->mempolicy;
+	int tmp;
+
+	if ((!old) || (old->policy == MPOL_DEFAULT))
+		return 0;
+
+	new = migrate_policy(task->mempolicy, node_map);
+	if (IS_ERR(new))
+		return (PTR_ERR(new));
+
+	mpol_get(new);
+	task->mempolicy = new;
+	mpol_free(old);
+
+	if (task->mempolicy->policy == MPOL_INTERLEAVE) {
+		/*
+		 * If the task is still running and allocating storage, this
+		 * is racy, but there is not much that can be done about it.
+		 */
+		tmp = task->il_next;
+		if (node_map[tmp] >= 0)
+			task->il_next = node_map[tmp];
+	}
+
+	return 0;
+
+}
+
+/*
+ * update a vma mempolicy based on a migration request
+ */
+int migrate_vma_policy(struct vm_area_struct *vma, unsigned int *node_map)
+{
+
+	struct mempolicy *new;
+
+	if (!vma->vm_policy || vma->vm_policy->policy == MPOL_DEFAULT)
+		return 0;
+
+	new = migrate_policy(vma->vm_policy, node_map);
+	if (IS_ERR(new))
+		return (PTR_ERR(new));
+
+	return(policy_vma(vma, new));
+}
Index: linux-2.6.12-rc5-mhp1-page-migration-export/mm/mmigrate.c
===================================================================
--- linux-2.6.12-rc5-mhp1-page-migration-export.orig/mm/mmigrate.c	2005-06-13 11:12:50.000000000 -0700
+++ linux-2.6.12-rc5-mhp1-page-migration-export/mm/mmigrate.c	2005-06-13 11:12:51.000000000 -0700
@@ -25,6 +25,7 @@
 #include <linux/mmigrate.h>
 #include <linux/delay.h>
 #include <linux/nodemask.h>
+#include <linux/mempolicy.h>
 #include <asm/bitops.h>
 
 /*
@@ -731,12 +732,21 @@ sys_migrate_pages(pid_t pid, __u32 count
 		node_map[tmp_old_nodes[i]] = tmp_new_nodes[i];
 
 	/* prepare for lru list manipulation */
-  	smp_call_function(&lru_add_drain_per_cpu, NULL, 0, 1);
+	smp_call_function(&lru_add_drain_per_cpu, NULL, 0, 1);
 	lru_add_drain();
 
+	/* update the process mempolicy, if needed */
+	ret = migrate_process_policy(task, node_map);
+	if (ret < 0)
+		goto out;
+
 	/* actually do the migration */
 	down_read(&mm->mmap_sem);
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+		/* update the vma mempolicy, if needed */
+		ret = migrate_vma_policy(vma, node_map);
+		if (ret < 0)
+			goto out_up_mmap_sem;
 		/* migrate the pages of this vma */
 		ret = migrate_vma(task, mm, vma, node_map);
 		if (ret < 0)

-- 
Best Regards,
Ray
-----------------------------------------------
Ray Bryant                       raybry@sgi.com
The box said: "Requires Windows 98 or better",
           so I installed Linux.
-----------------------------------------------
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