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cpuset: clean up cpuset hierarchy traversal code

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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>
This commit is contained in:
Li Zefan 2008-07-29 22:33:24 -07:00 committed by Linus Torvalds
parent 93a6557558
commit aeed682421
1 changed files with 8 additions and 13 deletions
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21
kernel/cpuset.c
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@ -54,7 +54,6 @@
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/atomic.h> #include <asm/atomic.h>
#include <linux/mutex.h> #include <linux/mutex.h>
#include <linux/kfifo.h>
#include <linux/workqueue.h> #include <linux/workqueue.h>
#include <linux/cgroup.h> #include <linux/cgroup.h>
@ -557,7 +556,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
* So the reverse nesting would risk an ABBA deadlock. * So the reverse nesting would risk an ABBA deadlock.
* *
* The three key local variables below are: * 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 * top-down scan of all cpusets. This scan loads a pointer
* to each cpuset marked is_sched_load_balance into the * to each cpuset marked is_sched_load_balance into the
* array 'csa'. For our purposes, rebuilding the schedulers * array 'csa'. For our purposes, rebuilding the schedulers
@ -592,7 +591,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
void rebuild_sched_domains(void) 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 *cp; /* scans q */
struct cpuset **csa; /* array of all cpuset ptrs */ struct cpuset **csa; /* array of all cpuset ptrs */
int csn; /* how many cpuset ptrs in csa so far */ int csn; /* how many cpuset ptrs in csa so far */
@ -602,7 +601,6 @@ void rebuild_sched_domains(void)
int ndoms; /* number of sched domains in result */ int ndoms; /* number of sched domains in result */
int nslot; /* next empty doms[] cpumask_t slot */ int nslot; /* next empty doms[] cpumask_t slot */
q = NULL;
csa = NULL; csa = NULL;
doms = NULL; doms = NULL;
dattr = NULL; dattr = NULL;
@ -622,20 +620,19 @@ void rebuild_sched_domains(void)
goto rebuild; 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); csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL);
if (!csa) if (!csa)
goto done; goto done;
csn = 0; csn = 0;
cp = &top_cpuset; list_add(&top_cpuset.stack_list, &q);
__kfifo_put(q, (void *)&cp, sizeof(cp)); while (!list_empty(&q)) {
while (__kfifo_get(q, (void *)&cp, sizeof(cp))) {
struct cgroup *cont; struct cgroup *cont;
struct cpuset *child; /* scans child cpusets of cp */ 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)) if (cpus_empty(cp->cpus_allowed))
continue; continue;
@ -652,7 +649,7 @@ void rebuild_sched_domains(void)
list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
child = cgroup_cs(cont); child = cgroup_cs(cont);
__kfifo_put(q, (void *)&child, sizeof(cp)); list_add_tail(&child->stack_list, &q);
} }
} }
@ -735,8 +732,6 @@ rebuild:
put_online_cpus(); put_online_cpus();
done: done:
if (q && !IS_ERR(q))
kfifo_free(q);
kfree(csa); kfree(csa);
/* Don't kfree(doms) -- partition_sched_domains() does that. */ /* Don't kfree(doms) -- partition_sched_domains() does that. */
/* Don't kfree(dattr) -- partition_sched_domains() does that. */ /* Don't kfree(dattr) -- partition_sched_domains() does that. */