Currently there is no interface to be called by a driver for user process
virtual range migration. This adds one function and exports to be then
used by drivers.
Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
include/linux/mempolicy.h | 2 ++
mm/mempolicy.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index ff0c6bc..b07d6dc 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -153,6 +153,8 @@ extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
const nodemask_t *mask);
extern unsigned int mempolicy_slab_node(void);
+extern int migrate_virtual_range(int pid, unsigned long vaddr,
+ unsigned long size, int nid);
extern enum zone_type policy_zone;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4482140..13cd5eb 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2919,3 +2919,48 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
nodemask_pr_args(&nodes));
}
+
+/*
+ * migrate_virtual_range - migrate all pages of a process faulted within
+ * a virtual address range to a specified node. This function is also
+ * exported to be used by device drivers dealing with CDM memory.
+ *
+ * @pid: Process ID of the target process
+ * @start: Start address of virtual range
+ * @end: End address of virtual range
+ * @nid: Target node for migration
+ *
+ * Returns number of pages that were not migrated in case of failure else
+ * returns 0 when its successful.
+ */
+int migrate_virtual_range(int pid, unsigned long start,
+ unsigned long end, int nid)
+{
+ struct mm_struct *mm;
+ int ret = 0;
+
+ LIST_HEAD(mlist);
+
+ if ((!start) || (!end)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ rcu_read_lock();
+ mm = find_task_by_vpid(pid)->mm;
+ rcu_read_unlock();
+
+ down_write(&mm->mmap_sem);
+ queue_pages_range(mm, start, end, &node_states[N_MEMORY],
+ MPOL_MF_MOVE_ALL | MPOL_MF_DISCONTIG_OK, &mlist);
+ if (!list_empty(&mlist)) {
+ ret = migrate_pages(&mlist, new_node_page, NULL,
+ nid, MIGRATE_SYNC, MR_NUMA_MISPLACED);
+ if (ret)
+ putback_movable_pages(&mlist);
+ }
+ up_write(&mm->mmap_sem);
+out:
+ return ret;
+}
+EXPORT_SYMBOL(migrate_virtual_range);
--
2.9.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
