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Commit 40df2deb authored by Li Zefan's avatar Li Zefan Committed by Tejun Heo
Browse files

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: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 06d6b3cb

kernel/cpuset.c

+7 −22
Original line number Diff line number Diff line
@@ -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]);

}



/*