aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/cpu.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c66
1 files changed, 32 insertions, 34 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 36e70845cfc3..208cf3497c10 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -97,7 +97,7 @@ static inline void check_for_tasks(int cpu)
97 (!cputime_eq(p->utime, cputime_zero) || 97 (!cputime_eq(p->utime, cputime_zero) ||
98 !cputime_eq(p->stime, cputime_zero))) 98 !cputime_eq(p->stime, cputime_zero)))
99 printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\ 99 printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\
100 (state = %ld, flags = %lx) \n", 100 (state = %ld, flags = %x) \n",
101 p->comm, p->pid, cpu, p->state, p->flags); 101 p->comm, p->pid, cpu, p->state, p->flags);
102 } 102 }
103 write_unlock_irq(&tasklist_lock); 103 write_unlock_irq(&tasklist_lock);
@@ -120,11 +120,13 @@ static int take_cpu_down(void *unused)
120} 120}
121 121
122/* Requires cpu_add_remove_lock to be held */ 122/* Requires cpu_add_remove_lock to be held */
123static int _cpu_down(unsigned int cpu) 123static int _cpu_down(unsigned int cpu, int tasks_frozen)
124{ 124{
125 int err; 125 int err, nr_calls = 0;
126 struct task_struct *p; 126 struct task_struct *p;
127 cpumask_t old_allowed, tmp; 127 cpumask_t old_allowed, tmp;
128 void *hcpu = (void *)(long)cpu;
129 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
128 130
129 if (num_online_cpus() == 1) 131 if (num_online_cpus() == 1)
130 return -EBUSY; 132 return -EBUSY;
@@ -132,12 +134,16 @@ static int _cpu_down(unsigned int cpu)
132 if (!cpu_online(cpu)) 134 if (!cpu_online(cpu))
133 return -EINVAL; 135 return -EINVAL;
134 136
135 err = raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE, 137 raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu);
136 (void *)(long)cpu); 138 err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
139 hcpu, -1, &nr_calls);
137 if (err == NOTIFY_BAD) { 140 if (err == NOTIFY_BAD) {
141 __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
142 hcpu, nr_calls, NULL);
138 printk("%s: attempt to take down CPU %u failed\n", 143 printk("%s: attempt to take down CPU %u failed\n",
139 __FUNCTION__, cpu); 144 __FUNCTION__, cpu);
140 return -EINVAL; 145 err = -EINVAL;
146 goto out_release;
141 } 147 }
142 148
143 /* Ensure that we are not runnable on dying cpu */ 149 /* Ensure that we are not runnable on dying cpu */
@@ -152,8 +158,8 @@ static int _cpu_down(unsigned int cpu)
152 158
153 if (IS_ERR(p) || cpu_online(cpu)) { 159 if (IS_ERR(p) || cpu_online(cpu)) {
154 /* CPU didn't die: tell everyone. Can't complain. */ 160 /* CPU didn't die: tell everyone. Can't complain. */
155 if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, 161 if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
156 (void *)(long)cpu) == NOTIFY_BAD) 162 hcpu) == NOTIFY_BAD)
157 BUG(); 163 BUG();
158 164
159 if (IS_ERR(p)) { 165 if (IS_ERR(p)) {
@@ -170,13 +176,9 @@ static int _cpu_down(unsigned int cpu)
170 /* This actually kills the CPU. */ 176 /* This actually kills the CPU. */
171 __cpu_die(cpu); 177 __cpu_die(cpu);
172 178
173 /* Move it here so it can run. */
174 kthread_bind(p, get_cpu());
175 put_cpu();
176
177 /* CPU is completely dead: tell everyone. Too late to complain. */ 179 /* CPU is completely dead: tell everyone. Too late to complain. */
178 if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD, 180 if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
179 (void *)(long)cpu) == NOTIFY_BAD) 181 hcpu) == NOTIFY_BAD)
180 BUG(); 182 BUG();
181 183
182 check_for_tasks(cpu); 184 check_for_tasks(cpu);
@@ -185,6 +187,8 @@ out_thread:
185 err = kthread_stop(p); 187 err = kthread_stop(p);
186out_allowed: 188out_allowed:
187 set_cpus_allowed(current, old_allowed); 189 set_cpus_allowed(current, old_allowed);
190out_release:
191 raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu);
188 return err; 192 return err;
189} 193}
190 194
@@ -196,7 +200,7 @@ int cpu_down(unsigned int cpu)
196 if (cpu_hotplug_disabled) 200 if (cpu_hotplug_disabled)
197 err = -EBUSY; 201 err = -EBUSY;
198 else 202 else
199 err = _cpu_down(cpu); 203 err = _cpu_down(cpu, 0);
200 204
201 mutex_unlock(&cpu_add_remove_lock); 205 mutex_unlock(&cpu_add_remove_lock);
202 return err; 206 return err;
@@ -204,15 +208,18 @@ int cpu_down(unsigned int cpu)
204#endif /*CONFIG_HOTPLUG_CPU*/ 208#endif /*CONFIG_HOTPLUG_CPU*/
205 209
206/* Requires cpu_add_remove_lock to be held */ 210/* Requires cpu_add_remove_lock to be held */
207static int __cpuinit _cpu_up(unsigned int cpu) 211static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
208{ 212{
209 int ret; 213 int ret, nr_calls = 0;
210 void *hcpu = (void *)(long)cpu; 214 void *hcpu = (void *)(long)cpu;
215 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
211 216
212 if (cpu_online(cpu) || !cpu_present(cpu)) 217 if (cpu_online(cpu) || !cpu_present(cpu))
213 return -EINVAL; 218 return -EINVAL;
214 219
215 ret = raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu); 220 raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu);
221 ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu,
222 -1, &nr_calls);
216 if (ret == NOTIFY_BAD) { 223 if (ret == NOTIFY_BAD) {
217 printk("%s: attempt to bring up CPU %u failed\n", 224 printk("%s: attempt to bring up CPU %u failed\n",
218 __FUNCTION__, cpu); 225 __FUNCTION__, cpu);
@@ -229,12 +236,13 @@ static int __cpuinit _cpu_up(unsigned int cpu)
229 BUG_ON(!cpu_online(cpu)); 236 BUG_ON(!cpu_online(cpu));
230 237
231 /* Now call notifier in preparation. */ 238 /* Now call notifier in preparation. */
232 raw_notifier_call_chain(&cpu_chain, CPU_ONLINE, hcpu); 239 raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
233 240
234out_notify: 241out_notify:
235 if (ret != 0) 242 if (ret != 0)
236 raw_notifier_call_chain(&cpu_chain, 243 __raw_notifier_call_chain(&cpu_chain,
237 CPU_UP_CANCELED, hcpu); 244 CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
245 raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu);
238 246
239 return ret; 247 return ret;
240} 248}
@@ -247,19 +255,13 @@ int __cpuinit cpu_up(unsigned int cpu)
247 if (cpu_hotplug_disabled) 255 if (cpu_hotplug_disabled)
248 err = -EBUSY; 256 err = -EBUSY;
249 else 257 else
250 err = _cpu_up(cpu); 258 err = _cpu_up(cpu, 0);
251 259
252 mutex_unlock(&cpu_add_remove_lock); 260 mutex_unlock(&cpu_add_remove_lock);
253 return err; 261 return err;
254} 262}
255 263
256#ifdef CONFIG_SUSPEND_SMP 264#ifdef CONFIG_SUSPEND_SMP
257/* Needed to prevent the microcode driver from requesting firmware in its CPU
258 * hotplug notifier during the suspend/resume.
259 */
260int suspend_cpu_hotplug;
261EXPORT_SYMBOL(suspend_cpu_hotplug);
262
263static cpumask_t frozen_cpus; 265static cpumask_t frozen_cpus;
264 266
265int disable_nonboot_cpus(void) 267int disable_nonboot_cpus(void)
@@ -267,7 +269,6 @@ int disable_nonboot_cpus(void)
267 int cpu, first_cpu, error = 0; 269 int cpu, first_cpu, error = 0;
268 270
269 mutex_lock(&cpu_add_remove_lock); 271 mutex_lock(&cpu_add_remove_lock);
270 suspend_cpu_hotplug = 1;
271 first_cpu = first_cpu(cpu_online_map); 272 first_cpu = first_cpu(cpu_online_map);
272 /* We take down all of the non-boot CPUs in one shot to avoid races 273 /* We take down all of the non-boot CPUs in one shot to avoid races
273 * with the userspace trying to use the CPU hotplug at the same time 274 * with the userspace trying to use the CPU hotplug at the same time
@@ -277,7 +278,7 @@ int disable_nonboot_cpus(void)
277 for_each_online_cpu(cpu) { 278 for_each_online_cpu(cpu) {
278 if (cpu == first_cpu) 279 if (cpu == first_cpu)
279 continue; 280 continue;
280 error = _cpu_down(cpu); 281 error = _cpu_down(cpu, 1);
281 if (!error) { 282 if (!error) {
282 cpu_set(cpu, frozen_cpus); 283 cpu_set(cpu, frozen_cpus);
283 printk("CPU%d is down\n", cpu); 284 printk("CPU%d is down\n", cpu);
@@ -294,7 +295,6 @@ int disable_nonboot_cpus(void)
294 } else { 295 } else {
295 printk(KERN_ERR "Non-boot CPUs are not disabled\n"); 296 printk(KERN_ERR "Non-boot CPUs are not disabled\n");
296 } 297 }
297 suspend_cpu_hotplug = 0;
298 mutex_unlock(&cpu_add_remove_lock); 298 mutex_unlock(&cpu_add_remove_lock);
299 return error; 299 return error;
300} 300}
@@ -309,10 +309,9 @@ void enable_nonboot_cpus(void)
309 if (cpus_empty(frozen_cpus)) 309 if (cpus_empty(frozen_cpus))
310 goto out; 310 goto out;
311 311
312 suspend_cpu_hotplug = 1;
313 printk("Enabling non-boot CPUs ...\n"); 312 printk("Enabling non-boot CPUs ...\n");
314 for_each_cpu_mask(cpu, frozen_cpus) { 313 for_each_cpu_mask(cpu, frozen_cpus) {
315 error = _cpu_up(cpu); 314 error = _cpu_up(cpu, 1);
316 if (!error) { 315 if (!error) {
317 printk("CPU%d is up\n", cpu); 316 printk("CPU%d is up\n", cpu);
318 continue; 317 continue;
@@ -320,7 +319,6 @@ void enable_nonboot_cpus(void)
320 printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); 319 printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
321 } 320 }
322 cpus_clear(frozen_cpus); 321 cpus_clear(frozen_cpus);
323 suspend_cpu_hotplug = 0;
324out: 322out:
325 mutex_unlock(&cpu_add_remove_lock); 323 mutex_unlock(&cpu_add_remove_lock);
326} 324}