Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Borislav Petkov:
- Do the push of pending hrtimers away from a CPU which is being
offlined earlier in the offlining process in order to prevent a
deadlock
* tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimers: Push pending hrtimers away from outgoing CPU earlier
+22
-24
+1
include/linux/cpuhotplug.h
+1
include/linux/cpuhotplug.h
+2
-2
include/linux/hrtimer.h
+2
-2
include/linux/hrtimer.h
···
531
531
532
532
int hrtimers_prepare_cpu(unsigned int cpu);
533
533
#ifdef CONFIG_HOTPLUG_CPU
534
-
int hrtimers_dead_cpu(unsigned int cpu);
534
+
int hrtimers_cpu_dying(unsigned int cpu);
535
535
#else
536
-
#define hrtimers_dead_cpu NULL
536
+
#define hrtimers_cpu_dying NULL
537
537
#endif
538
538
539
539
#endif
+7
-1
kernel/cpu.c
+7
-1
kernel/cpu.c
···
2113
2113
[CPUHP_HRTIMERS_PREPARE] = {
2114
2114
.name = "hrtimers:prepare",
2115
2115
.startup.single = hrtimers_prepare_cpu,
2116
-
.teardown.single = hrtimers_dead_cpu,
2116
+
.teardown.single = NULL,
2117
2117
},
2118
2118
[CPUHP_SMPCFD_PREPARE] = {
2119
2119
.name = "smpcfd:prepare",
···
2205
2205
.startup.single = NULL,
2206
2206
.teardown.single = smpcfd_dying_cpu,
2207
2207
},
2208
+
[CPUHP_AP_HRTIMERS_DYING] = {
2209
+
.name = "hrtimers:dying",
2210
+
.startup.single = NULL,
2211
+
.teardown.single = hrtimers_cpu_dying,
2212
+
},
2213
+
2208
2214
/* Entry state on starting. Interrupts enabled from here on. Transient
2209
2215
* state for synchronsization */
2210
2216
[CPUHP_AP_ONLINE] = {
+12
-21
kernel/time/hrtimer.c
+12
-21
kernel/time/hrtimer.c
···
2219
2219
}
2220
2220
}
2221
2221
2222
-
int hrtimers_dead_cpu(unsigned int scpu)
2222
+
int hrtimers_cpu_dying(unsigned int dying_cpu)
2223
2223
{
2224
2224
struct hrtimer_cpu_base *old_base, *new_base;
2225
-
int i;
2225
+
int i, ncpu = cpumask_first(cpu_active_mask);
2226
2226
2227
-
BUG_ON(cpu_online(scpu));
2228
-
tick_cancel_sched_timer(scpu);
2227
+
tick_cancel_sched_timer(dying_cpu);
2229
2228
2230
-
/*
2231
-
* this BH disable ensures that raise_softirq_irqoff() does
2232
-
* not wakeup ksoftirqd (and acquire the pi-lock) while
2233
-
* holding the cpu_base lock
2234
-
*/
2235
-
local_bh_disable();
2236
-
local_irq_disable();
2237
-
old_base = &per_cpu(hrtimer_bases, scpu);
2238
-
new_base = this_cpu_ptr(&hrtimer_bases);
2229
+
old_base = this_cpu_ptr(&hrtimer_bases);
2230
+
new_base = &per_cpu(hrtimer_bases, ncpu);
2231
+
2239
2232
/*
2240
2233
* The caller is globally serialized and nobody else
2241
2234
* takes two locks at once, deadlock is not possible.
2242
2235
*/
2243
-
raw_spin_lock(&new_base->lock);
2244
-
raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
2236
+
raw_spin_lock(&old_base->lock);
2237
+
raw_spin_lock_nested(&new_base->lock, SINGLE_DEPTH_NESTING);
2245
2238
2246
2239
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
2247
2240
migrate_hrtimer_list(&old_base->clock_base[i],
···
2245
2252
* The migration might have changed the first expiring softirq
2246
2253
* timer on this CPU. Update it.
2247
2254
*/
2248
-
hrtimer_update_softirq_timer(new_base, false);
2255
+
__hrtimer_get_next_event(new_base, HRTIMER_ACTIVE_SOFT);
2256
+
/* Tell the other CPU to retrigger the next event */
2257
+
smp_call_function_single(ncpu, retrigger_next_event, NULL, 0);
2249
2258
2250
-
raw_spin_unlock(&old_base->lock);
2251
2259
raw_spin_unlock(&new_base->lock);
2260
+
raw_spin_unlock(&old_base->lock);
2252
2261
2253
-
/* Check, if we got expired work to do */
2254
-
__hrtimer_peek_ahead_timers();
2255
-
local_irq_enable();
2256
-
local_bh_enable();
2257
2262
return 0;
2258
2263
}
2259
2264