cpuset: remove unneeded NODEMASK_ALLOC() in cpuset_attach() (c8163ca8) · Commits · 戴 / test

oldcs->mems_allowed is not modified during cpuset_attach(), so we don't have to copy it to a buffer allocated by NODEMASK_ALLOC(). Just pass it to cpuset_migrate_mm(). Signed-off-by:

Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by:

David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpuset.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -1438,10 +1438,9 @@ static void cpuset_attach(struct cgroup_subsys ss, struct cgroup cont,
		struct mm_struct *mm;
		struct cpuset *cs = cgroup_cs(cont);
		struct cpuset *oldcs = cgroup_cs(oldcont);
		NODEMASK_ALLOC(nodemask_t, from, GFP_KERNEL);
		NODEMASK_ALLOC(nodemask_t, to, GFP_KERNEL);

		if (from == NULL \|\| to == NULL)
		if (to == NULL)
		goto alloc_fail;

		if (cs == &top_cpuset) {
		@@ -1463,18 +1462,16 @@ static void cpuset_attach(struct cgroup_subsys ss, struct cgroup cont,
		}

		/* change mm; only needs to be done once even if threadgroup */
		*from = oldcs->mems_allowed;
		*to = cs->mems_allowed;
		mm = get_task_mm(tsk);
		if (mm) {
		mpol_rebind_mm(mm, to);
		if (is_memory_migrate(cs))
		cpuset_migrate_mm(mm, from, to);
		cpuset_migrate_mm(mm, &oldcs->mems_allowed, to);
		mmput(mm);
		}

		alloc_fail:
		NODEMASK_FREE(from);
		NODEMASK_FREE(to);
		}

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