Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"Three fixlets from the timer departement:
- Update the timekeeper before updating vsyscall and pvclock. This
fixes the kvm-clock regression reported by Chris and Paolo.
- Use the proper irq work interface from NMI. This fixes the
regression reported by Catalin and Dave.
- Clarify the compat_nanosleep error handling mechanism to avoid
future confusion"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Update timekeeper before updating vsyscall and pvclock
compat: nanosleep: Clarify error handling
nohz: Restore NMI safe local irq work for local nohz kick
+39
-11
+1
-6
include/linux/tick.h
+1
-6
include/linux/tick.h
···
183
183
184
184
extern void tick_nohz_init(void);
185
185
extern void __tick_nohz_full_check(void);
186
+
extern void tick_nohz_full_kick(void);
186
187
extern void tick_nohz_full_kick_cpu(int cpu);
187
-
188
-
static inline void tick_nohz_full_kick(void)
189
-
{
190
-
tick_nohz_full_kick_cpu(smp_processor_id());
191
-
}
192
-
193
188
extern void tick_nohz_full_kick_all(void);
194
189
extern void __tick_nohz_task_switch(struct task_struct *tsk);
195
190
#else
+21
-3
kernel/compat.c
+21
-3
kernel/compat.c
···
226
226
ret = hrtimer_nanosleep_restart(restart);
227
227
set_fs(oldfs);
228
228
229
-
if (ret) {
229
+
if (ret == -ERESTART_RESTARTBLOCK) {
230
230
rmtp = restart->nanosleep.compat_rmtp;
231
231
232
232
if (rmtp && compat_put_timespec(&rmt, rmtp))
···
256
256
HRTIMER_MODE_REL, CLOCK_MONOTONIC);
257
257
set_fs(oldfs);
258
258
259
-
if (ret) {
259
+
/*
260
+
* hrtimer_nanosleep() can only return 0 or
261
+
* -ERESTART_RESTARTBLOCK here because:
262
+
*
263
+
* - we call it with HRTIMER_MODE_REL and therefor exclude the
264
+
* -ERESTARTNOHAND return path.
265
+
*
266
+
* - we supply the rmtp argument from the task stack (due to
267
+
* the necessary compat conversion. So the update cannot
268
+
* fail, which excludes the -EFAULT return path as well. If
269
+
* it fails nevertheless we have a bigger problem and wont
270
+
* reach this place anymore.
271
+
*
272
+
* - if the return value is 0, we do not have to update rmtp
273
+
* because there is no remaining time.
274
+
*
275
+
* We check for -ERESTART_RESTARTBLOCK nevertheless if the
276
+
* core implementation decides to return random nonsense.
277
+
*/
278
+
if (ret == -ERESTART_RESTARTBLOCK) {
260
279
struct restart_block *restart
261
280
= ¤t_thread_info()->restart_block;
262
281
···
285
266
if (rmtp && compat_put_timespec(&rmt, rmtp))
286
267
return -EFAULT;
287
268
}
288
-
289
269
return ret;
290
270
}
291
271
+14
kernel/time/tick-sched.c
+14
kernel/time/tick-sched.c
···
225
225
};
226
226
227
227
/*
228
+
* Kick this CPU if it's full dynticks in order to force it to
229
+
* re-evaluate its dependency on the tick and restart it if necessary.
230
+
* This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(),
231
+
* is NMI safe.
232
+
*/
233
+
void tick_nohz_full_kick(void)
234
+
{
235
+
if (!tick_nohz_full_cpu(smp_processor_id()))
236
+
return;
237
+
238
+
irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
239
+
}
240
+
241
+
/*
228
242
* Kick the CPU if it's full dynticks in order to force it to
229
243
* re-evaluate its dependency on the tick and restart it if necessary.
230
244
*/
+3
-2
kernel/time/timekeeping.c
+3
-2
kernel/time/timekeeping.c
···
442
442
tk->ntp_error = 0;
443
443
ntp_clear();
444
444
}
445
-
update_vsyscall(tk);
446
-
update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
447
445
448
446
tk_update_ktime_data(tk);
447
+
448
+
update_vsyscall(tk);
449
+
update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
449
450
450
451
if (action & TK_MIRROR)
451
452
memcpy(&shadow_timekeeper, &tk_core.timekeeper,