[PATCH-for-4.17] xen/sched: migrate timers to correct cpus after suspend

Message ID	20221021145357.17931-1-jgross@suse.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <xen-devel-bounces@lists.xenproject.org> Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" <xen-devel-bounces@lists.xenproject.org> From: Juergen Gross <jgross@suse.com> To: xen-devel@lists.xenproject.org Cc: Juergen Gross <jgross@suse.com>, George Dunlap <george.dunlap@citrix.com>, Dario Faggioli <dfaggioli@suse.com>, Meng Xu <mengxu@cis.upenn.edu>, Henry Wang <Henry.Wang@arm.com> Subject: [PATCH-for-4.17] xen/sched: migrate timers to correct cpus after suspend Date: Fri, 21 Oct 2022 16:53:57 +0200 Message-Id: <20221021145357.17931-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	[PATCH-for-4.17] xen/sched: migrate timers to correct cpus after suspend \| expand [PATCH-for-4.17] xen/sched: migrate timers to correct cpus after suspend

diff --git a/xen/common/sched/core.c b/xen/common/sched/core.c index 23fa6845a8..142d03ade5 100644 --- a/xen/common/sched/core.c +++ b/xen/common/sched/core.c @@ -1284,6 +1284,29 @@ static int cpu_disable_scheduler_check(unsigned int cpu) return 0; } +/* + * Called after a cpu has come up again in a suspend/resume cycle. + * Migrate all timers for this cpu (they have been migrated to cpu 0 when the + * cpu was going down). + * Note that only timers related to a physical cpu are migrated, not the ones + * related to a vcpu or domain. + */ +void sched_migrate_timers(unsigned int cpu) +{ + struct sched_resource *sr; + + rcu_read_lock(&sched_res_rculock); + + sr = get_sched_res(cpu); + if ( sr->master_cpu == cpu ) + { + migrate_timer(&sr->s_timer, cpu); + sched_move_timers(sr->scheduler, sr); + } + + rcu_read_unlock(&sched_res_rculock); +} + /* * In general, this must be called with the scheduler lock held, because the * adjust_affinity hook may want to modify the vCPU state. However, when the diff --git a/xen/common/sched/cpupool.c b/xen/common/sched/cpupool.c index b2c6f520c3..bdf6030ab0 100644 --- a/xen/common/sched/cpupool.c +++ b/xen/common/sched/cpupool.c @@ -1035,6 +1035,8 @@ static int cf_check cpu_callback( case CPU_ONLINE: if ( system_state <= SYS_STATE_active ) rc = cpupool_cpu_add(cpu); + else + sched_migrate_timers(cpu); break; case CPU_DOWN_PREPARE: /* Suspend/Resume don't change assignments of cpus to cpupools. */ diff --git a/xen/common/sched/credit.c b/xen/common/sched/credit.c index 47945c2834..f2cd3d9da3 100644 --- a/xen/common/sched/credit.c +++ b/xen/common/sched/credit.c @@ -614,6 +614,18 @@ init_pdata(struct csched_private *prv, struct csched_pcpu *spc, int cpu) spc->nr_runnable = 0; } +static void cf_check +csched_move_timers(const struct scheduler *ops, struct sched_resource *sr) +{ + struct csched_private *prv = CSCHED_PRIV(ops); + struct csched_pcpu *spc = sr->sched_priv; + + if ( sr->master_cpu == prv->master ) + migrate_timer(&prv->master_ticker, prv->master); + + migrate_timer(&spc->ticker, sr->master_cpu); +} + /* Change the scheduler of cpu to us (Credit). */ static spinlock_t *cf_check csched_switch_sched(struct scheduler *new_ops, unsigned int cpu, @@ -2264,6 +2276,7 @@ static const struct scheduler sched_credit_def = { .switch_sched = csched_switch_sched, .alloc_domdata = csched_alloc_domdata, .free_domdata = csched_free_domdata, + .move_timers = csched_move_timers, }; REGISTER_SCHEDULER(sched_credit_def); diff --git a/xen/common/sched/private.h b/xen/common/sched/private.h index 0126a4bb9e..0527a8c70d 100644 --- a/xen/common/sched/private.h +++ b/xen/common/sched/private.h @@ -331,6 +331,8 @@ struct scheduler { struct xen_sysctl_scheduler_op *); void (*dump_settings) (const struct scheduler *); void (*dump_cpu_state) (const struct scheduler *, int); + void (*move_timers) (const struct scheduler *, + struct sched_resource *); }; static inline int sched_init(struct scheduler *s) @@ -485,6 +487,13 @@ static inline int sched_adjust_cpupool(const struct scheduler *s, return s->adjust_global ? s->adjust_global(s, op) : 0; } +static inline void sched_move_timers(const struct scheduler *s, + struct sched_resource *sr) +{ + if ( s->move_timers ) + s->move_timers(s, sr); +} + static inline void sched_unit_pause_nosync(const struct sched_unit *unit) { struct vcpu *v; @@ -622,6 +631,7 @@ struct cpu_rm_data *alloc_cpu_rm_data(unsigned int cpu, bool aff_alloc); void free_cpu_rm_data(struct cpu_rm_data *mem, unsigned int cpu); int schedule_cpu_rm(unsigned int cpu, struct cpu_rm_data *mem); int sched_move_domain(struct domain *d, struct cpupool *c); +void sched_migrate_timers(unsigned int cpu); struct cpupool *cpupool_get_by_id(unsigned int poolid); void cpupool_put(struct cpupool *pool); int cpupool_add_domain(struct domain *d, unsigned int poolid); diff --git a/xen/common/sched/rt.c b/xen/common/sched/rt.c index 1f8d074884..d443cd5831 100644 --- a/xen/common/sched/rt.c +++ b/xen/common/sched/rt.c @@ -750,6 +750,27 @@ rt_switch_sched(struct scheduler *new_ops, unsigned int cpu, return &prv->lock; } +static void move_repl_timer(struct rt_private *prv, unsigned int old_cpu) +{ + cpumask_t *online = get_sched_res(old_cpu)->cpupool->res_valid; + unsigned int new_cpu = cpumask_cycle(old_cpu, online); + + /* + * Make sure the timer run on one of the cpus that are still available + * to this scheduler. If there aren't any left, it means it's the time + * to just kill it. + */ + if ( new_cpu >= nr_cpu_ids ) + { + kill_timer(&prv->repl_timer); + dprintk(XENLOG_DEBUG, "RTDS: timer killed on cpu %d\n", old_cpu); + } + else + { + migrate_timer(&prv->repl_timer, new_cpu); + } +} + static void cf_check rt_deinit_pdata(const struct scheduler *ops, void *pcpu, int cpu) { @@ -759,25 +780,25 @@ rt_deinit_pdata(const struct scheduler *ops, void *pcpu, int cpu) spin_lock_irqsave(&prv->lock, flags); if ( prv->repl_timer.cpu == cpu ) - { - cpumask_t *online = get_sched_res(cpu)->cpupool->res_valid; - unsigned int new_cpu = cpumask_cycle(cpu, online); + move_repl_timer(prv, cpu); - /* - * Make sure the timer run on one of the cpus that are still available - * to this scheduler. If there aren't any left, it means it's the time - * to just kill it. - */ - if ( new_cpu >= nr_cpu_ids ) - { - kill_timer(&prv->repl_timer); - dprintk(XENLOG_DEBUG, "RTDS: timer killed on cpu %d\n", cpu); - } - else - { - migrate_timer(&prv->repl_timer, new_cpu); - } - } + spin_unlock_irqrestore(&prv->lock, flags); +} + +static void cf_check +rt_move_timers(const struct scheduler *ops, struct sched_resource *sr) +{ + unsigned long flags; + struct rt_private *prv = rt_priv(ops); + unsigned int old_cpu; + + spin_lock_irqsave(&prv->lock, flags); + + old_cpu = prv->repl_timer.cpu; + if ( prv->repl_timer.status != TIMER_STATUS_invalid && + prv->repl_timer.status != TIMER_STATUS_killed && + !cpumask_test_cpu(old_cpu, sr->cpupool->res_valid) ) + move_repl_timer(prv, old_cpu); spin_unlock_irqrestore(&prv->lock, flags); } @@ -1561,6 +1582,7 @@ static const struct scheduler sched_rtds_def = { .sleep = rt_unit_sleep, .wake = rt_unit_wake, .context_saved = rt_context_saved, + .move_timers = rt_move_timers, }; REGISTER_SCHEDULER(sched_rtds_def);

[PATCH-for-4.17] xen/sched: migrate timers to correct cpus after suspend

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