From 2341d1b6598c7146d64a5050b53a72a5a819617f Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 7 Jan 2009 18:08:42 -0800 Subject: 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 Cc: Ingo Molnar Cc: Rusty Russell Acked-by: Mike Travis Cc: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index afa29cfc5bb..1e32e6b380a 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -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; } -- cgit v1.2.3