[PATCH 2/6] cpuset: remove on stack cpumask_t in cpuset_can_attach()

From: Li Zefan
Date: Wed Dec 31 2008 - 03:37:15 EST


Impact: redue stack usage

Just use cs->cpus_allowed, and no need to allocate a cpumask_var_t.

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
---
kernel/cpuset.c | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 41c2343..afa29cf 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1311,20 +1311,19 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
struct cgroup *cont, struct task_struct *tsk)
{
struct cpuset *cs = cgroup_cs(cont);
+ int ret = 0;

if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
- if (tsk->flags & PF_THREAD_BOUND) {
- cpumask_t mask;

+ if (tsk->flags & PF_THREAD_BOUND) {
mutex_lock(&callback_mutex);
- mask = cs->cpus_allowed;
+ if (!cpus_equal(tsk->cpus_allowed, cs->cpus_allowed))
+ ret = -EINVAL;
mutex_unlock(&callback_mutex);
- if (!cpus_equal(tsk->cpus_allowed, mask))
- return -EINVAL;
}

- return security_task_setscheduler(tsk, 0, NULL);
+ return ret < 0 ? ret : security_task_setscheduler(tsk, 0, NULL);
}

static void cpuset_attach(struct cgroup_subsys *ss,
--
1.5.4.rc3



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