Commit-ID: 5ed63b199c5b58ed150ce50f1ea68de54669b13f
Gitweb: http://git.kernel.org/tip/5ed63b199c5b58ed150ce50f1ea68de54669b13f
Author: Iulia Manda <iulia.manda21@xxxxxxxxx>
AuthorDate: Mon, 17 Mar 2014 15:21:21 +0200
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Wed, 14 May 2014 09:46:14 -0700
torture: Notice if an all-zero cpumask is passed inside a critical section
In torture_shuffle_tasks function, the check if an all-zero mask can
be passed to set_cpus_allowed_ptr() is redundant after clearing the
shuffle_idle_cpu bit. If the mask had more than one bit set, after
clearing a bit it has at least one bit set. If the mask had only
one bit set, a check is made at the beginning, where the function
returns, as there is no need to shuffle only one cpu.
Also, this code is executed inside a critical section, delimited by
get_online_cpus(), and put_online_cpus(), preventing CPUs from leaving between
the check of num_online_cpus and the calls to set_cpus_allowed_ptr() function.
Signed-off-by: Iulia Manda <iulia.manda21@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
kernel/torture.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/kernel/torture.c b/kernel/torture.c
index bc0ee38..ae1723a 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -335,13 +335,8 @@ static void torture_shuffle_tasks(void)
shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask);
if (shuffle_idle_cpu >= nr_cpu_ids)
shuffle_idle_cpu = -1;
- if (shuffle_idle_cpu != -1) {
+ else
cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask);
- if (cpumask_empty(shuffle_tmp_mask)) {
- put_online_cpus();
- return;
- }
- }
mutex_lock(&shuffle_task_mutex);
list_for_each_entry(stp, &shuffle_task_list, st_l)
--
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