X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=kernel%2Fcpuset.c;h=15b3ea693225c85e437bb754850b4cc0aa34c4f5;hb=71043e2a6ef7d6305867fdeb97155233f6e52033;hp=4772034b4b17062a4506bc4f437c599b8d5f2ac3;hpb=825e587af2e90e9b953849f3347a01d8f383d577;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 4772034..15b3ea6 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -974,12 +974,6 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
  *    Temporarilly set tasks mems_allowed to target nodes of migration,
  *    so that the migration code can allocate pages on these nodes.
  *
- *    Call holding cpuset_mutex, so current's cpuset won't change
- *    during this call, as manage_mutex holds off any cpuset_attach()
- *    calls.  Therefore we don't need to take task_lock around the
- *    call to guarantee_online_mems(), as we know no one is changing
- *    our task's cpuset.
- *
  *    While the mm_struct we are migrating is typically from some
  *    other task, the task_struct mems_allowed that we are hacking
  *    is for our current task, which must allocate new pages for that
@@ -996,8 +990,10 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
 
 	do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);
 
+	rcu_read_lock();
 	mems_cs = effective_nodemask_cpuset(task_cs(tsk));
 	guarantee_online_mems(mems_cs, &tsk->mems_allowed);
+	rcu_read_unlock();
 }
 
 /*
@@ -1026,7 +1022,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
 	task_lock(tsk);
 	/*
 	 * Determine if a loop is necessary if another thread is doing
-	 * get_mems_allowed().  If at least one node remains unchanged and
+	 * read_mems_allowed_begin().  If at least one node remains unchanged and
 	 * tsk does not have a mempolicy, then an empty nodemask will not be
 	 * possible when mems_allowed is larger than a word.
 	 */
@@ -1240,7 +1236,13 @@ done:
 
 int current_cpuset_is_being_rebound(void)
 {
-	return task_cs(current) == cpuset_being_rebound;
+	int ret;
+
+	rcu_read_lock();
+	ret = task_cs(current) == cpuset_being_rebound;
+	rcu_read_unlock();
+
+	return ret;
 }
 
 static int update_relax_domain_level(struct cpuset *cs, s64 val)
@@ -1731,66 +1733,41 @@ out_unlock:
  * used, list of ranges of sequential numbers, is variable length,
  * and since these maps can change value dynamically, one could read
  * gibberish by doing partial reads while a list was changing.
- * A single large read to a buffer that crosses a page boundary is
- * ok, because the result being copied to user land is not recomputed
- * across a page fault.
  */
-
-static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
+static int cpuset_common_seq_show(struct seq_file *sf, void *v)
 {
-	size_t count;
+	struct cpuset *cs = css_cs(seq_css(sf));
+	cpuset_filetype_t type = seq_cft(sf)->private;
+	ssize_t count;
+	char *buf, *s;
+	int ret = 0;
 
-	mutex_lock(&callback_mutex);
-	count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
-	mutex_unlock(&callback_mutex);
-
-	return count;
-}
-
-static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs)
-{
-	size_t count;
+	count = seq_get_buf(sf, &buf);
+	s = buf;
 
 	mutex_lock(&callback_mutex);
-	count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed);
-	mutex_unlock(&callback_mutex);
-
-	return count;
-}
-
-static ssize_t cpuset_common_file_read(struct cgroup_subsys_state *css,
-				       struct cftype *cft, struct file *file,
-				       char __user *buf, size_t nbytes,
-				       loff_t *ppos)
-{
-	struct cpuset *cs = css_cs(css);
-	cpuset_filetype_t type = cft->private;
-	char *page;
-	ssize_t retval = 0;
-	char *s;
-
-	if (!(page = (char *)__get_free_page(GFP_TEMPORARY)))
-		return -ENOMEM;
-
-	s = page;
 
 	switch (type) {
 	case FILE_CPULIST:
-		s += cpuset_sprintf_cpulist(s, cs);
+		s += cpulist_scnprintf(s, count, cs->cpus_allowed);
 		break;
 	case FILE_MEMLIST:
-		s += cpuset_sprintf_memlist(s, cs);
+		s += nodelist_scnprintf(s, count, cs->mems_allowed);
 		break;
 	default:
-		retval = -EINVAL;
-		goto out;
+		ret = -EINVAL;
+		goto out_unlock;
 	}
-	*s++ = '\n';
 
-	retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page);
-out:
-	free_page((unsigned long)page);
-	return retval;
+	if (s < buf + count - 1) {
+		*s++ = '\n';
+		seq_commit(sf, s - buf);
+	} else {
+		seq_commit(sf, -1);
+	}
+out_unlock:
+	mutex_unlock(&callback_mutex);
+	return ret;
 }
 
 static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft)
@@ -1847,7 +1824,7 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
 static struct cftype files[] = {
 	{
 		.name = "cpus",
-		.read = cpuset_common_file_read,
+		.seq_show = cpuset_common_seq_show,
 		.write_string = cpuset_write_resmask,
 		.max_write_len = (100U + 6 * NR_CPUS),
 		.private = FILE_CPULIST,
@@ -1855,7 +1832,7 @@ static struct cftype files[] = {
 
 	{
 		.name = "mems",
-		.read = cpuset_common_file_read,
+		.seq_show = cpuset_common_seq_show,
 		.write_string = cpuset_write_resmask,
 		.max_write_len = (100U + 6 * MAX_NUMNODES),
 		.private = FILE_MEMLIST,
@@ -2511,9 +2488,9 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 
 	task_lock(current);
 	cs = nearest_hardwall_ancestor(task_cs(current));
+	allowed = node_isset(node, cs->mems_allowed);
 	task_unlock(current);
 
-	allowed = node_isset(node, cs->mems_allowed);
 	mutex_unlock(&callback_mutex);
 	return allowed;
 }