X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fmempolicy.c;h=4f71cfd29c6fa4859c151442176434f48aec748d;hb=8f2e9f157a94f444dad974b088b853ac40785b02;hp=e93cc740c22b4e24caf5c0ba531126b34f300b00;hpb=36177ba655c238e33400cc2837a28720b62784bd;p=pandora-kernel.git

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e93cc740c22b..4f71cfd29c6f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -422,6 +422,37 @@ static int contextualize_policy(int mode, nodemask_t *nodes)
 	return mpol_check_policy(mode, nodes);
 }
 
+
+/*
+ * Update task->flags PF_MEMPOLICY bit: set iff non-default
+ * mempolicy.  Allows more rapid checking of this (combined perhaps
+ * with other PF_* flag bits) on memory allocation hot code paths.
+ *
+ * If called from outside this file, the task 'p' should -only- be
+ * a newly forked child not yet visible on the task list, because
+ * manipulating the task flags of a visible task is not safe.
+ *
+ * The above limitation is why this routine has the funny name
+ * mpol_fix_fork_child_flag().
+ *
+ * It is also safe to call this with a task pointer of current,
+ * which the static wrapper mpol_set_task_struct_flag() does,
+ * for use within this file.
+ */
+
+void mpol_fix_fork_child_flag(struct task_struct *p)
+{
+	if (p->mempolicy)
+		p->flags |= PF_MEMPOLICY;
+	else
+		p->flags &= ~PF_MEMPOLICY;
+}
+
+static void mpol_set_task_struct_flag(void)
+{
+	mpol_fix_fork_child_flag(current);
+}
+
 /* Set the process memory policy */
 long do_set_mempolicy(int mode, nodemask_t *nodes)
 {
@@ -434,6 +465,7 @@ long do_set_mempolicy(int mode, nodemask_t *nodes)
 		return PTR_ERR(new);
 	mpol_free(current->mempolicy);
 	current->mempolicy = new;
+	mpol_set_task_struct_flag();
 	if (new && new->policy == MPOL_INTERLEAVE)
 		current->il_next = first_node(new->v.nodes);
 	return 0;