cpuset: cleanup guarantee_online_{cpus|mems}()

- We never pass a NULL @cs to these functions.
- The top cpuset always has some online cpus/mems.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2013-06-05 17:15:23 +08:00 committed by Tejun Heo
parent 06d6b3cbdf
commit 40df2deb50

View File

@ -304,53 +304,38 @@ static struct file_system_type cpuset_fs_type = {
/*
* Return in pmask the portion of a cpusets's cpus_allowed that
* 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_mask. Or if passed a NULL cs from an exit'ing
* task, return cpu_online_mask.
* until we find one that does have some online cpus. The top
* cpuset always has some cpus online.
*
* One way or another, we guarantee to return some non-empty subset
* of cpu_online_mask.
*
* Call with callback_mutex held.
*/
static void guarantee_online_cpus(const struct cpuset *cs,
struct cpumask *pmask)
{
while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
cs = parent_cs(cs);
if (cs)
cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
else
cpumask_copy(pmask, cpu_online_mask);
BUG_ON(!cpumask_intersects(pmask, cpu_online_mask));
}
/*
* Return in *pmask the portion of a cpusets's mems_allowed that
* are online, with memory. If none are online with memory, walk
* up the cpuset hierarchy until we find one that does have some
* online mems. If we get all the way to the top and still haven't
* found any online mems, return node_states[N_MEMORY].
* online mems. The top cpuset always has some mems online.
*
* One way or another, we guarantee to return some non-empty subset
* of node_states[N_MEMORY].
*
* Call with callback_mutex held.
*/
static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
{
while (cs && !nodes_intersects(cs->mems_allowed,
node_states[N_MEMORY]))
while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY]))
cs = parent_cs(cs);
if (cs)
nodes_and(*pmask, cs->mems_allowed,
node_states[N_MEMORY]);
else
*pmask = node_states[N_MEMORY];
BUG_ON(!nodes_intersects(*pmask, node_states[N_MEMORY]));
nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]);
}
/*