Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 22 insertions, 68 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a09ac2b9a661..14f7070b4ba2 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -270,11 +270,11 @@ static struct file_system_type cpuset_fs_type = {
  * are online.  If none are online, walk up the cpuset hierarchy
  * until we find one that does have some online cpus.  If we get
  * all the way to the top and still haven't found any online cpus,
- * return cpu_online_map.  Or if passed a NULL cs from an exit'ing
- * task, return cpu_online_map.
+ * return cpu_online_mask.  Or if passed a NULL cs from an exit'ing
+ * task, return cpu_online_mask.
  *
  * One way or another, we guarantee to return some non-empty subset
- * of cpu_online_map.
+ * of cpu_online_mask.
  *
  * Call with callback_mutex held.
  */
@@ -867,7 +867,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 	int retval;
 	int is_load_balanced;
 
-	/* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
+	/* top_cpuset.cpus_allowed tracks cpu_online_mask; it's read-only */
 	if (cs == &top_cpuset)
 		return -EACCES;
 
@@ -964,7 +964,6 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
 {
 	bool need_loop;
 
-repeat:
 	/*
 	 * Allow tasks that have access to memory reserves because they have
 	 * been OOM killed to get memory anywhere.
@@ -983,45 +982,19 @@ repeat:
 	 */
 	need_loop = task_has_mempolicy(tsk) ||
 			!nodes_intersects(*newmems, tsk->mems_allowed);
-	nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems);
-	mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1);
-
-	/*
-	 * ensure checking ->mems_allowed_change_disable after setting all new
-	 * allowed nodes.
-	 *
-	 * the read-side task can see an nodemask with new allowed nodes and
-	 * old allowed nodes. and if it allocates page when cpuset clears newly
-	 * disallowed ones continuous, it can see the new allowed bits.
-	 *
-	 * And if setting all new allowed nodes is after the checking, setting
-	 * all new allowed nodes and clearing newly disallowed ones will be done
-	 * continuous, and the read-side task may find no node to alloc page.
-	 */
-	smp_mb();
 
-	/*
-	 * Allocation of memory is very fast, we needn't sleep when waiting
-	 * for the read-side.
-	 */
-	while (need_loop && ACCESS_ONCE(tsk->mems_allowed_change_disable)) {
-		task_unlock(tsk);
-		if (!task_curr(tsk))
-			yield();
-		goto repeat;
-	}
+	if (need_loop)
+		write_seqcount_begin(&tsk->mems_allowed_seq);
 
-	/*
-	 * ensure checking ->mems_allowed_change_disable before clearing all new
-	 * disallowed nodes.
-	 *
-	 * if clearing newly disallowed bits before the checking, the read-side
-	 * task may find no node to alloc page.
-	 */
-	smp_mb();
+	nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems);
+	mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1);
 
 	mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP2);
 	tsk->mems_allowed = *newmems;
+
+	if (need_loop)
+		write_seqcount_end(&tsk->mems_allowed_seq);
+
 	task_unlock(tsk);
 }
 
@@ -1399,8 +1372,7 @@ static nodemask_t cpuset_attach_nodemask_from;
 static nodemask_t cpuset_attach_nodemask_to;
 
 /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-			     struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
 	struct cpuset *cs = cgroup_cs(cgrp);
 	struct task_struct *task;
@@ -1436,8 +1408,7 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
 	return 0;
 }
 
-static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-			  struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
 	struct mm_struct *mm;
 	struct task_struct *task;
@@ -1833,8 +1804,7 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont)
  * (and likewise for mems) to the new cgroup. Called with cgroup_mutex
  * held.
  */
-static void cpuset_post_clone(struct cgroup_subsys *ss,
-			      struct cgroup *cgroup)
+static void cpuset_post_clone(struct cgroup *cgroup)
 {
 	struct cgroup *parent, *child;
 	struct cpuset *cs, *parent_cs;
@@ -1857,13 +1827,10 @@ static void cpuset_post_clone(struct cgroup_subsys *ss,
 
 /*
  *	cpuset_create - create a cpuset
- *	ss:	cpuset cgroup subsystem
  *	cont:	control group that the new cpuset will be part of
  */
 
-static struct cgroup_subsys_state *cpuset_create(
-	struct cgroup_subsys *ss,
-	struct cgroup *cont)
+static struct cgroup_subsys_state *cpuset_create(struct cgroup *cont)
 {
 	struct cpuset *cs;
 	struct cpuset *parent;
@@ -1902,7 +1869,7 @@ static struct cgroup_subsys_state *cpuset_create(
  * will call async_rebuild_sched_domains().
  */
 
-static void cpuset_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
+static void cpuset_destroy(struct cgroup *cont)
 {
 	struct cpuset *cs = cgroup_cs(cont);
 
@@ -2182,7 +2149,7 @@ void __init cpuset_init_smp(void)
  *
  * Description: Returns the cpumask_var_t cpus_allowed of the cpuset
  * attached to the specified @tsk.  Guaranteed to return some non-empty
- * subset of cpu_online_map, even if this means going outside the
+ * subset of cpu_online_mask, even if this means going outside the
  * tasks cpuset.
  **/
 
@@ -2195,10 +2162,9 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
 	mutex_unlock(&callback_mutex);
 }
 
-int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
+void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
 {
 	const struct cpuset *cs;
-	int cpu;
 
 	rcu_read_lock();
 	cs = task_cs(tsk);
@@ -2219,22 +2185,10 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
 	 * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary
 	 * set any mask even if it is not right from task_cs() pov,
 	 * the pending set_cpus_allowed_ptr() will fix things.
+	 *
+	 * select_fallback_rq() will fix things ups and set cpu_possible_mask
+	 * if required.
 	 */
-
-	cpu = cpumask_any_and(&tsk->cpus_allowed, cpu_active_mask);
-	if (cpu >= nr_cpu_ids) {
-		/*
-		 * Either tsk->cpus_allowed is wrong (see above) or it
-		 * is actually empty. The latter case is only possible
-		 * if we are racing with remove_tasks_in_empty_cpuset().
-		 * Like above we can temporary set any mask and rely on
-		 * set_cpus_allowed_ptr() as synchronization point.
-		 */
-		do_set_cpus_allowed(tsk, cpu_possible_mask);
-		cpu = cpumask_any(cpu_active_mask);
-	}
-
-	return cpu;
 }
 
 void cpuset_init_current_mems_allowed(void)