cpuset: clean up cpuset hierarchy traversal code
Use cpuset.stack_list rather than kfifo, so we avoid memory allocation
for kfifo.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 7a82e90..d5ab79c 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -54,7 +54,6 @@
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <linux/mutex.h>
-#include <linux/kfifo.h>
#include <linux/workqueue.h>
#include <linux/cgroup.h>
@@ -557,7 +556,7 @@
* So the reverse nesting would risk an ABBA deadlock.
*
* The three key local variables below are:
- * q - a kfifo queue of cpuset pointers, used to implement a
+ * q - a linked-list queue of cpuset pointers, used to implement a
* top-down scan of all cpusets. This scan loads a pointer
* to each cpuset marked is_sched_load_balance into the
* array 'csa'. For our purposes, rebuilding the schedulers
@@ -592,7 +591,7 @@
void rebuild_sched_domains(void)
{
- struct kfifo *q; /* queue of cpusets to be scanned */
+ LIST_HEAD(q); /* queue of cpusets to be scanned*/
struct cpuset *cp; /* scans q */
struct cpuset **csa; /* array of all cpuset ptrs */
int csn; /* how many cpuset ptrs in csa so far */
@@ -602,7 +601,6 @@
int ndoms; /* number of sched domains in result */
int nslot; /* next empty doms[] cpumask_t slot */
- q = NULL;
csa = NULL;
doms = NULL;
dattr = NULL;
@@ -622,20 +620,19 @@
goto rebuild;
}
- q = kfifo_alloc(number_of_cpusets * sizeof(cp), GFP_KERNEL, NULL);
- if (IS_ERR(q))
- goto done;
csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL);
if (!csa)
goto done;
csn = 0;
- cp = &top_cpuset;
- __kfifo_put(q, (void *)&cp, sizeof(cp));
- while (__kfifo_get(q, (void *)&cp, sizeof(cp))) {
+ list_add(&top_cpuset.stack_list, &q);
+ while (!list_empty(&q)) {
struct cgroup *cont;
struct cpuset *child; /* scans child cpusets of cp */
+ cp = list_first_entry(&q, struct cpuset, stack_list);
+ list_del(q.next);
+
if (cpus_empty(cp->cpus_allowed))
continue;
@@ -652,7 +649,7 @@
list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
child = cgroup_cs(cont);
- __kfifo_put(q, (void *)&child, sizeof(cp));
+ list_add_tail(&child->stack_list, &q);
}
}
@@ -735,8 +732,6 @@
put_online_cpus();
done:
- if (q && !IS_ERR(q))
- kfifo_free(q);
kfree(csa);
/* Don't kfree(doms) -- partition_sched_domains() does that. */
/* Don't kfree(dattr) -- partition_sched_domains() does that. */