cpuset: convert cpuset_attach() to use cpumask_var_t

Impact: reduce stack usage

Allocate a global cpumask_var_t at boot, and use it in cpuset_attach(), so
we won't fail cpuset_attach().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.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 2009-01-07 18:08:42 -08:00 committed by Linus Torvalds
parent 5771f0a223
commit 2341d1b659

View File

@ -1306,6 +1306,9 @@ static int fmeter_getrate(struct fmeter *fmp)
return val;
}
/* Protected by cgroup_lock */
static cpumask_var_t cpus_attach;
/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup_subsys *ss,
struct cgroup *cont, struct task_struct *tsk)
@ -1330,7 +1333,6 @@ static void cpuset_attach(struct cgroup_subsys *ss,
struct cgroup *cont, struct cgroup *oldcont,
struct task_struct *tsk)
{
cpumask_t cpus;
nodemask_t from, to;
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
@ -1338,13 +1340,13 @@ static void cpuset_attach(struct cgroup_subsys *ss,
int err;
if (cs == &top_cpuset) {
cpus = cpu_possible_map;
cpumask_copy(cpus_attach, cpu_possible_mask);
} else {
mutex_lock(&callback_mutex);
guarantee_online_cpus(cs, &cpus);
guarantee_online_cpus(cs, cpus_attach);
mutex_unlock(&callback_mutex);
}
err = set_cpus_allowed_ptr(tsk, &cpus);
err = set_cpus_allowed_ptr(tsk, cpus_attach);
if (err)
return;
@ -1357,7 +1359,6 @@ static void cpuset_attach(struct cgroup_subsys *ss,
cpuset_migrate_mm(mm, &from, &to);
mmput(mm);
}
}
/* The various types of files and directories in a cpuset file system */
@ -1838,6 +1839,9 @@ int __init cpuset_init(void)
if (err < 0)
return err;
if (!alloc_cpumask_var(&cpus_attach, GFP_KERNEL))
BUG();
number_of_cpusets = 1;
return 0;
}