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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-14 17:50:49 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-14 17:50:49 -0400
commit948769a5ba304ed3329a2f42ee3561f04a0b5692 (patch)
tree7430c5fcae383d90c7c0101364440ac24e5cbc18 /kernel
parente18425a0abc8eafa8e98ecffac517bb0c0904f4b (diff)
parent773dc8eacaedb2e8c8d0defb5de2c66ea7dc4a08 (diff)
Merge branch 'sched/new-API-sched_setscheduler' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched/new-API-sched_setscheduler' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: add new API sched_setscheduler_nocheck: add a flag to control access checks
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c48
-rw-r--r--kernel/softirq.c2
-rw-r--r--kernel/stop_machine.c2
3 files changed, 38 insertions, 14 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index c74b0d23c752..2317a2178104 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4995,16 +4995,8 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
4995 set_load_weight(p); 4995 set_load_weight(p);
4996} 4996}
4997 4997
4998/** 4998static int __sched_setscheduler(struct task_struct *p, int policy,
4999 * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. 4999 struct sched_param *param, bool user)
5000 * @p: the task in question.
5001 * @policy: new policy.
5002 * @param: structure containing the new RT priority.
5003 *
5004 * NOTE that the task may be already dead.
5005 */
5006int sched_setscheduler(struct task_struct *p, int policy,
5007 struct sched_param *param)
5008{ 5000{
5009 int retval, oldprio, oldpolicy = -1, on_rq, running; 5001 int retval, oldprio, oldpolicy = -1, on_rq, running;
5010 unsigned long flags; 5002 unsigned long flags;
@@ -5036,7 +5028,7 @@ recheck:
5036 /* 5028 /*
5037 * Allow unprivileged RT tasks to decrease priority: 5029 * Allow unprivileged RT tasks to decrease priority:
5038 */ 5030 */
5039 if (!capable(CAP_SYS_NICE)) { 5031 if (user && !capable(CAP_SYS_NICE)) {
5040 if (rt_policy(policy)) { 5032 if (rt_policy(policy)) {
5041 unsigned long rlim_rtprio; 5033 unsigned long rlim_rtprio;
5042 5034
@@ -5072,7 +5064,8 @@ recheck:
5072 * Do not allow realtime tasks into groups that have no runtime 5064 * Do not allow realtime tasks into groups that have no runtime
5073 * assigned. 5065 * assigned.
5074 */ 5066 */
5075 if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0) 5067 if (user
5068 && rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
5076 return -EPERM; 5069 return -EPERM;
5077#endif 5070#endif
5078 5071
@@ -5121,8 +5114,39 @@ recheck:
5121 5114
5122 return 0; 5115 return 0;
5123} 5116}
5117
5118/**
5119 * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
5120 * @p: the task in question.
5121 * @policy: new policy.
5122 * @param: structure containing the new RT priority.
5123 *
5124 * NOTE that the task may be already dead.
5125 */
5126int sched_setscheduler(struct task_struct *p, int policy,
5127 struct sched_param *param)
5128{
5129 return __sched_setscheduler(p, policy, param, true);
5130}
5124EXPORT_SYMBOL_GPL(sched_setscheduler); 5131EXPORT_SYMBOL_GPL(sched_setscheduler);
5125 5132
5133/**
5134 * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
5135 * @p: the task in question.
5136 * @policy: new policy.
5137 * @param: structure containing the new RT priority.
5138 *
5139 * Just like sched_setscheduler, only don't bother checking if the
5140 * current context has permission. For example, this is needed in
5141 * stop_machine(): we create temporary high priority worker threads,
5142 * but our caller might not have that capability.
5143 */
5144int sched_setscheduler_nocheck(struct task_struct *p, int policy,
5145 struct sched_param *param)
5146{
5147 return __sched_setscheduler(p, policy, param, false);
5148}
5149
5126static int 5150static int
5127do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) 5151do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
5128{ 5152{
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 36e061740047..afd9120c2fc4 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -645,7 +645,7 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb,
645 645
646 p = per_cpu(ksoftirqd, hotcpu); 646 p = per_cpu(ksoftirqd, hotcpu);
647 per_cpu(ksoftirqd, hotcpu) = NULL; 647 per_cpu(ksoftirqd, hotcpu) = NULL;
648 sched_setscheduler(p, SCHED_FIFO, &param); 648 sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
649 kthread_stop(p); 649 kthread_stop(p);
650 takeover_tasklets(hotcpu); 650 takeover_tasklets(hotcpu);
651 break; 651 break;
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index b7350bbfb076..ba9b2054ecbd 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -187,7 +187,7 @@ struct task_struct *__stop_machine_run(int (*fn)(void *), void *data,
187 struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; 187 struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
188 188
189 /* One high-prio thread per cpu. We'll do this one. */ 189 /* One high-prio thread per cpu. We'll do this one. */
190 sched_setscheduler(p, SCHED_FIFO, &param); 190 sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
191 kthread_bind(p, cpu); 191 kthread_bind(p, cpu);
192 wake_up_process(p); 192 wake_up_process(p);
193 wait_for_completion(&smdata.done); 193 wait_for_completion(&smdata.done);