Unverified Commit cc8c90c4 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!3021 fix CFS bandwidth vs. hrtimer self deadlock 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yu Liao <liaoyu15@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/NZDCWD6EP57SW57EVG6DBJMUZAHYA22R/ 
Thomas Gleixner (1):
  hrtimers: Push pending hrtimers away from outgoing CPU earlier

Yu Liao (1):
  cpu/hotplug: fix kabi breakage in enum cpuhp_state


-- 
2.25.1
 
https://gitee.com/openeuler/kernel/issues/I8JEVI 
 
Link:https://gitee.com/openeuler/kernel/pulls/3021

 

Reviewed-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: default avatarXie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: default avatarLiu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parents e19ed41c 48725c8f

include/linux/hrtimer.h

+2 −2
Original line number Diff line number Diff line
@@ -508,9 +508,9 @@ extern void sysrq_timer_list_show(void); 


int hrtimers_prepare_cpu(unsigned int cpu);

#ifdef CONFIG_HOTPLUG_CPU

int hrtimers_dead_cpu(unsigned int cpu);

int hrtimers_cpu_dying(unsigned int cpu);

#else

#define hrtimers_dead_cpu	NULL

static inline int hrtimers_cpu_dying(unsigned int cpu) { return 0; }

#endif



#endif

include/linux/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -220,5 +220,6 @@ int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, 
int smpcfd_prepare_cpu(unsigned int cpu);

int smpcfd_dead_cpu(unsigned int cpu);

int smpcfd_dying_cpu(unsigned int cpu);

int smpcfd_and_hrtimer_dying_cpu(unsigned int cpu);



#endif /* __LINUX_SMP_H */

kernel/cpu.c

+15 −2
Original line number Diff line number Diff line
@@ -1390,7 +1390,7 @@ static struct cpuhp_step cpuhp_hp_states[] = { 
	[CPUHP_HRTIMERS_PREPARE] = {

		.name			= "hrtimers:prepare",

		.startup.single		= hrtimers_prepare_cpu,

		.teardown.single	= hrtimers_dead_cpu,

		.teardown.single	= NULL,

	},

	[CPUHP_SMPCFD_PREPARE] = {

		.name			= "smpcfd:prepare",
@@ -1452,11 +1452,24 @@ static struct cpuhp_step cpuhp_hp_states[] = { 
		.startup.single		= NULL,

		.teardown.single	= rcutree_dying_cpu,

	},

	/*

	 * In order to fix the kabi breakage, we had to move the hrtimers:dying

	 * step into smpcfd:dying and create a new function smpcfd_and_hrtimer_dying_cpu().

	 * Please ensure that there are no other steps with teardown handler

	 * between smpcfd:dying and cpu:teardown.

	 */

	[CPUHP_AP_SMPCFD_DYING] = {

		.name			= "smpcfd:dying",

		.startup.single		= NULL,

		.teardown.single	= smpcfd_dying_cpu,

		.teardown.single	= smpcfd_and_hrtimer_dying_cpu,

	},



	/*

	 * Attention: Please do not add steps between smpcfd:dying

	 * and ap:online. Please refer to the above for specific

	 * reasons.

	 */



	/* Entry state on starting. Interrupts enabled from here on. Transient

	 * state for synchronsization */

	[CPUHP_AP_ONLINE] = {

kernel/smp.c

+8 −0
Original line number Diff line number Diff line
@@ -71,6 +71,14 @@ int smpcfd_dead_cpu(unsigned int cpu) 
	return 0;

}



int smpcfd_and_hrtimer_dying_cpu(unsigned int cpu)

{

	hrtimers_cpu_dying(cpu);

	smpcfd_dying_cpu(cpu);



	return 0;

}



int smpcfd_dying_cpu(unsigned int cpu)

{

	/*

kernel/time/hrtimer.c

+12 −21
Original line number Diff line number Diff line
@@ -1922,29 +1922,22 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, 
	}

}



int hrtimers_dead_cpu(unsigned int scpu)

int hrtimers_cpu_dying(unsigned int dying_cpu)

{

	struct hrtimer_cpu_base *old_base, *new_base;

	int i;

	int i, ncpu = cpumask_first(cpu_active_mask);



	BUG_ON(cpu_online(scpu));

	tick_cancel_sched_timer(scpu);

	tick_cancel_sched_timer(dying_cpu);



	old_base = this_cpu_ptr(&hrtimer_bases);

	new_base = &per_cpu(hrtimer_bases, ncpu);



	/*

	 * 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(&new_base->lock);

	raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);

	raw_spin_lock(&old_base->lock);

	raw_spin_lock_nested(&new_base->lock, SINGLE_DEPTH_NESTING);



	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {

		migrate_hrtimer_list(&old_base->clock_base[i],
@@ -1955,15 +1948,13 @@ int hrtimers_dead_cpu(unsigned int scpu) 
	 * The migration might have changed the first expiring softirq

	 * timer on this CPU. Update it.

	 */

	hrtimer_update_softirq_timer(new_base, false);

	__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);



	raw_spin_unlock(&old_base->lock);

	raw_spin_unlock(&new_base->lock);

	raw_spin_unlock(&old_base->lock);



	/* Check, if we got expired work to do */

	__hrtimer_peek_ahead_timers();

	local_irq_enable();

	local_bh_enable();

	return 0;

}