asgardius/android_kernel_motorola_sm6225
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Revert "hrtimers: Push pending hrtimers away from outgoing CPU earlier"

Browse source 
This reverts commit 9a2fc41acb which is
commit 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ifdc5474de6e7488eb24959df1697b61b2e3e7880
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-12-18 18:44:38 +00:00 committed by Treehugger Robot
parent 8e0beabeb4
commit 2c61eff508
4 changed files with 24 additions and 22 deletions
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1
include/linux/cpuhotplug.h
View file

@ -145,7 +145,6 @@ enum cpuhp_state {
CPUHP_AP_ARM_CORESIGHT_STARTING,
CPUHP_AP_ARM64_ISNDEP_STARTING,
CPUHP_AP_SMPCFD_DYING,
CPUHP_AP_HRTIMERS_DYING,
CPUHP_AP_X86_TBOOT_DYING,
CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
CPUHP_AP_ONLINE,

4
include/linux/hrtimer.h
View file

@ -497,9 +497,9 @@ extern void sysrq_timer_list_show(void);
int hrtimers_prepare_cpu(unsigned int cpu);
#ifdef CONFIG_HOTPLUG_CPU
int hrtimers_cpu_dying(unsigned int cpu);
int hrtimers_dead_cpu(unsigned int cpu);
#else
#define hrtimers_cpu_dying NULL
#define hrtimers_dead_cpu NULL
#endif
#endif

8
kernel/cpu.c
View file

@ -1464,7 +1464,7 @@ static struct cpuhp_step cpuhp_hp_states[] = {
[CPUHP_HRTIMERS_PREPARE] = {
.name = "hrtimers:prepare",
.startup.single = hrtimers_prepare_cpu,
.teardown.single = NULL,
.teardown.single = hrtimers_dead_cpu,
},
[CPUHP_SMPCFD_PREPARE] = {
.name = "smpcfd:prepare",
@ -1531,12 +1531,6 @@ static struct cpuhp_step cpuhp_hp_states[] = {
.startup.single = NULL,
.teardown.single = smpcfd_dying_cpu,
},
[CPUHP_AP_HRTIMERS_DYING] = {
.name = "hrtimers:dying",
.startup.single = NULL,
.teardown.single = hrtimers_cpu_dying,
},
/* Entry state on starting. Interrupts enabled from here on. Transient
* state for synchronsization */
[CPUHP_AP_ONLINE] = {

33
kernel/time/hrtimer.c
View file

@ -1922,22 +1922,29 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
}
}
int hrtimers_cpu_dying(unsigned int dying_cpu)
int hrtimers_dead_cpu(unsigned int scpu)
{
struct hrtimer_cpu_base *old_base, *new_base;
int i, ncpu = cpumask_first(cpu_active_mask);
int i;
tick_cancel_sched_timer(dying_cpu);
old_base = this_cpu_ptr(&hrtimer_bases);
new_base = &per_cpu(hrtimer_bases, ncpu);
BUG_ON(cpu_online(scpu));
tick_cancel_sched_timer(scpu);
/*
* this BH disable ensures that raise_softirq_irqoff() does
* not wakeup ksoftirqd (and acquire the pi-lock) while
* holding the cpu_base lock
*/
local_bh_disable();
local_irq_disable();
old_base = &per_cpu(hrtimer_bases, scpu);
new_base = this_cpu_ptr(&hrtimer_bases);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
*/
raw_spin_lock(&old_base->lock);
raw_spin_lock_nested(&new_base->lock, SINGLE_DEPTH_NESTING);
raw_spin_lock(&new_base->lock);
raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
migrate_hrtimer_list(&old_base->clock_base[i],
@ -1948,13 +1955,15 @@ int hrtimers_cpu_dying(unsigned int dying_cpu)
* The migration might have changed the first expiring softirq
* timer on this CPU. Update it.
*/
__hrtimer_get_next_event(new_base, HRTIMER_ACTIVE_SOFT);
/* Tell the other CPU to retrigger the next event */
smp_call_function_single(ncpu, retrigger_next_event, NULL, 0);
hrtimer_update_softirq_timer(new_base, false);
raw_spin_unlock(&new_base->lock);
raw_spin_unlock(&old_base->lock);
raw_spin_unlock(&new_base->lock);
/* Check, if we got expired work to do */
__hrtimer_peek_ahead_timers();
local_irq_enable();
local_bh_enable();
return 0;
}