[v2,2/3] xen/sched: carve out memory allocation and freeing from schedule_cpu_rm()

Message ID	20220815110410.19872-3-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State	Superseded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> Subject: [PATCH v2 2/3] xen/sched: carve out memory allocation and freeing from schedule_cpu_rm() Date: Mon, 15 Aug 2022 13:04:09 +0200 Message-Id: <20220815110410.19872-3-jgross@suse.com> In-Reply-To: <20220815110410.19872-1-jgross@suse.com> References: <20220815110410.19872-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	xen/sched: fix cpu hotplug \| expand [v2,0/3] xen/sched: fix cpu hotplug [v2,1/3] xen/sched: introduce cpupool_update_node_affinity() [v2,2/3] xen/sched: carve out memory allocation and freeing from schedule_cpu_rm() [v2,3/3] xen/sched: fix cpu hotplug

diff --git a/xen/common/sched/core.c b/xen/common/sched/core.c index 085a9dd335..d0b6513b6f 100644 --- a/xen/common/sched/core.c +++ b/xen/common/sched/core.c @@ -3237,6 +3237,65 @@ out: return ret; } +static struct cpu_rm_data *schedule_cpu_rm_alloc(unsigned int cpu) +{ + struct cpu_rm_data *data; + const struct sched_resource *sr; + unsigned int idx; + + rcu_read_lock(&sched_res_rculock); + + sr = get_sched_res(cpu); + data = xmalloc_flex_struct(struct cpu_rm_data, sr, sr->granularity - 1); + if ( !data ) + goto out; + + data->old_ops = sr->scheduler; + data->vpriv_old = idle_vcpu[cpu]->sched_unit->priv; + data->ppriv_old = sr->sched_priv; + + for ( idx = 0; idx < sr->granularity - 1; idx++ ) + { + data->sr[idx] = sched_alloc_res(); + if ( data->sr[idx] ) + { + data->sr[idx]->sched_unit_idle = sched_alloc_unit_mem(); + if ( !data->sr[idx]->sched_unit_idle ) + { + sched_res_free(&data->sr[idx]->rcu); + data->sr[idx] = NULL; + } + } + if ( !data->sr[idx] ) + { + while ( idx > 0 ) + sched_res_free(&data->sr[--idx]->rcu); + XFREE(data); + goto out; + } + + data->sr[idx]->curr = data->sr[idx]->sched_unit_idle; + data->sr[idx]->scheduler = &sched_idle_ops; + data->sr[idx]->granularity = 1; + + /* We want the lock not to change when replacing the resource. */ + data->sr[idx]->schedule_lock = sr->schedule_lock; + } + + out: + rcu_read_unlock(&sched_res_rculock); + + return data; +} + +static void schedule_cpu_rm_free(struct cpu_rm_data *mem, unsigned int cpu) +{ + sched_free_udata(mem->old_ops, mem->vpriv_old); + sched_free_pdata(mem->old_ops, mem->ppriv_old, cpu); + + xfree(mem); +} + /* * Remove a pCPU from its cpupool. Its scheduler becomes &sched_idle_ops * (the idle scheduler). @@ -3245,53 +3304,23 @@ out: */ int schedule_cpu_rm(unsigned int cpu) { - void *ppriv_old, *vpriv_old; - struct sched_resource *sr, **sr_new = NULL; + struct sched_resource *sr; + struct cpu_rm_data *data; struct sched_unit *unit; - struct scheduler *old_ops; spinlock_t *old_lock; unsigned long flags; - int idx, ret = -ENOMEM; + int idx = 0; unsigned int cpu_iter; + data = schedule_cpu_rm_alloc(cpu); + if ( !data ) + return -ENOMEM; + rcu_read_lock(&sched_res_rculock); sr = get_sched_res(cpu); - old_ops = sr->scheduler; - if ( sr->granularity > 1 ) - { - sr_new = xmalloc_array(struct sched_resource *, sr->granularity - 1); - if ( !sr_new ) - goto out; - for ( idx = 0; idx < sr->granularity - 1; idx++ ) - { - sr_new[idx] = sched_alloc_res(); - if ( sr_new[idx] ) - { - sr_new[idx]->sched_unit_idle = sched_alloc_unit_mem(); - if ( !sr_new[idx]->sched_unit_idle ) - { - sched_res_free(&sr_new[idx]->rcu); - sr_new[idx] = NULL; - } - } - if ( !sr_new[idx] ) - { - for ( idx--; idx >= 0; idx-- ) - sched_res_free(&sr_new[idx]->rcu); - goto out; - } - sr_new[idx]->curr = sr_new[idx]->sched_unit_idle; - sr_new[idx]->scheduler = &sched_idle_ops; - sr_new[idx]->granularity = 1; - - /* We want the lock not to change when replacing the resource. */ - sr_new[idx]->schedule_lock = sr->schedule_lock; - } - } - - ret = 0; + ASSERT(sr->granularity); ASSERT(sr->cpupool != NULL); ASSERT(cpumask_test_cpu(cpu, &cpupool_free_cpus)); ASSERT(!cpumask_test_cpu(cpu, sr->cpupool->cpu_valid)); @@ -3299,10 +3328,6 @@ int schedule_cpu_rm(unsigned int cpu) /* See comment in schedule_cpu_add() regarding lock switching. */ old_lock = pcpu_schedule_lock_irqsave(cpu, &flags); - vpriv_old = idle_vcpu[cpu]->sched_unit->priv; - ppriv_old = sr->sched_priv; - - idx = 0; for_each_cpu ( cpu_iter, sr->cpus ) { per_cpu(sched_res_idx, cpu_iter) = 0; @@ -3316,27 +3341,27 @@ int schedule_cpu_rm(unsigned int cpu) else { /* Initialize unit. */ - unit = sr_new[idx]->sched_unit_idle; - unit->res = sr_new[idx]; + unit = data->sr[idx]->sched_unit_idle; + unit->res = data->sr[idx]; unit->is_running = true; sched_unit_add_vcpu(unit, idle_vcpu[cpu_iter]); sched_domain_insert_unit(unit, idle_vcpu[cpu_iter]->domain); /* Adjust cpu masks of resources (old and new). */ cpumask_clear_cpu(cpu_iter, sr->cpus); - cpumask_set_cpu(cpu_iter, sr_new[idx]->cpus); + cpumask_set_cpu(cpu_iter, data->sr[idx]->cpus); cpumask_set_cpu(cpu_iter, &sched_res_mask); /* Init timer. */ - init_timer(&sr_new[idx]->s_timer, s_timer_fn, NULL, cpu_iter); + init_timer(&data->sr[idx]->s_timer, s_timer_fn, NULL, cpu_iter); /* Last resource initializations and insert resource pointer. */ - sr_new[idx]->master_cpu = cpu_iter; - set_sched_res(cpu_iter, sr_new[idx]); + data->sr[idx]->master_cpu = cpu_iter; + set_sched_res(cpu_iter, data->sr[idx]); /* Last action: set the new lock pointer. */ smp_mb(); - sr_new[idx]->schedule_lock = &sched_free_cpu_lock; + data->sr[idx]->schedule_lock = &sched_free_cpu_lock; idx++; } @@ -3352,16 +3377,12 @@ int schedule_cpu_rm(unsigned int cpu) /* _Not_ pcpu_schedule_unlock(): schedule_lock may have changed! */ spin_unlock_irqrestore(old_lock, flags); - sched_deinit_pdata(old_ops, ppriv_old, cpu); - - sched_free_udata(old_ops, vpriv_old); - sched_free_pdata(old_ops, ppriv_old, cpu); + sched_deinit_pdata(data->old_ops, data->ppriv_old, cpu); -out: rcu_read_unlock(&sched_res_rculock); - xfree(sr_new); + schedule_cpu_rm_free(data, cpu); - return ret; + return 0; } struct scheduler *scheduler_get_default(void) diff --git a/xen/common/sched/private.h b/xen/common/sched/private.h index 38251b1f7b..601d639699 100644 --- a/xen/common/sched/private.h +++ b/xen/common/sched/private.h @@ -600,6 +600,15 @@ struct affinity_masks { bool update_node_aff_alloc(struct affinity_masks *affinity); void update_node_aff_free(struct affinity_masks *affinity); + +/* Memory allocation related data for schedule_cpu_rm(). */ +struct cpu_rm_data { + const struct scheduler *old_ops; + void *ppriv_old; + void *vpriv_old; + struct sched_resource *sr[]; +}; + void sched_rm_cpu(unsigned int cpu); const cpumask_t *sched_get_opt_cpumask(enum sched_gran opt, unsigned int cpu); void schedule_dump(struct cpupool *c);

[v2,2/3] xen/sched: carve out memory allocation and freeing from schedule_cpu_rm()

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