diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-11-25 02:35:11 +1030 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-24 17:51:59 +0100 |
| commit | 5a16f3d30ca4e3f166d691220c003066a14e32b5 (patch) | |
| tree | 8e65fa8dc91f12a6be37c36d71bb48d2c97d6447 /kernel/sched.c | |
| parent | e76bd8d9850c2296a7e8e24c9dce9b5e6b55fe2f (diff) | |
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t.
Impact: stack usage reduction
Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space on the stack. cpumask_var_t is just a struct cpumask for
!CONFIG_CPUMASK_OFFSTACK.
Note the removal of the initializer of new_mask: since the first thing
we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed
that to "cpumask_and(new_mask, in_mask, cpus_allowed);".
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index f7dee2029e4..2d4ff91e0c9 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5378,8 +5378,7 @@ out_unlock: long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) { - cpumask_t cpus_allowed; - cpumask_t new_mask = *in_mask; + cpumask_var_t cpus_allowed, new_mask; struct task_struct *p; int retval; @@ -5401,6 +5400,14 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) get_task_struct(p); read_unlock(&tasklist_lock); + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_put_task; + } + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_free_cpus_allowed; + } retval = -EPERM; if ((current->euid != p->euid) && (current->euid != p->uid) && !capable(CAP_SYS_NICE)) @@ -5410,24 +5417,28 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) if (retval) goto out_unlock; - cpuset_cpus_allowed(p, &cpus_allowed); - cpus_and(new_mask, new_mask, cpus_allowed); + cpuset_cpus_allowed(p, cpus_allowed); + cpumask_and(new_mask, in_mask, cpus_allowed); again: - retval = set_cpus_allowed_ptr(p, &new_mask); + retval = set_cpus_allowed_ptr(p, new_mask); if (!retval) { - cpuset_cpus_allowed(p, &cpus_allowed); - if (!cpus_subset(new_mask, cpus_allowed)) { + cpuset_cpus_allowed(p, cpus_allowed); + if (!cpumask_subset(new_mask, cpus_allowed)) { /* * We must have raced with a concurrent cpuset * update. Just reset the cpus_allowed to the * cpuset's cpus_allowed */ - new_mask = cpus_allowed; + cpumask_copy(new_mask, cpus_allowed); goto again; } } out_unlock: + free_cpumask_var(new_mask); +out_free_cpus_allowed: + free_cpumask_var(cpus_allowed); +out_put_task: put_task_struct(p); put_online_cpus(); return retval; @@ -5453,14 +5464,17 @@ static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr) { - cpumask_t new_mask; + cpumask_var_t new_mask; int retval; - retval = get_user_cpu_mask(user_mask_ptr, len, &new_mask); - if (retval) - return retval; + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; - return sched_setaffinity(pid, &new_mask); + retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); + if (retval == 0) + retval = sched_setaffinity(pid, new_mask); + free_cpumask_var(new_mask); + return retval; } long sched_getaffinity(pid_t pid, cpumask_t *mask) |