[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen/sched: carve out memory allocation and freeing from schedule_cpu_rm()
commit d42be6f83480b3ada286dc18444331a816be88a3 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Mon Sep 5 09:00:04 2022 +0200 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Mon Sep 5 11:42:30 2022 +0100 xen/sched: carve out memory allocation and freeing from schedule_cpu_rm() In order to prepare not allocating or freeing memory from schedule_cpu_rm(), move this functionality to dedicated functions. For now call those functions from schedule_cpu_rm(). No change of behavior expected. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- xen/common/sched/core.c | 143 +++++++++++++++++++++++++++------------------ xen/common/sched/private.h | 11 ++++ 2 files changed, 98 insertions(+), 56 deletions(-) diff --git a/xen/common/sched/core.c b/xen/common/sched/core.c index 5f1a265889..588826cdbd 100644 --- a/xen/common/sched/core.c +++ b/xen/common/sched/core.c @@ -3237,6 +3237,75 @@ out: return ret; } +/* + * Allocate all memory needed for free_cpu_rm_data(), as allocations cannot + * be made in stop_machine() context. + * + * Between alloc_cpu_rm_data() and the real cpu removal action the relevant + * contents of struct sched_resource can't change, as the cpu in question is + * locked against any other movement to or from cpupools, and the data copied + * by alloc_cpu_rm_data() is modified only in case the cpu in question is + * being moved from or to a cpupool. + */ +struct cpu_rm_data *alloc_cpu_rm_data(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; +} + +void free_cpu_rm_data(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 +3314,23 @@ 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 = alloc_cpu_rm_data(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 +3338,6 @@ 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 +3351,27 @@ 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 +3387,12 @@ 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); + free_cpu_rm_data(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 2b04b01a0c..e286849a13 100644 --- a/xen/common/sched/private.h +++ b/xen/common/sched/private.h @@ -600,6 +600,15 @@ struct affinity_masks { bool alloc_affinity_masks(struct affinity_masks *affinity); void free_affinity_masks(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); @@ -608,6 +617,8 @@ struct scheduler *scheduler_alloc(unsigned int sched_id); void scheduler_free(struct scheduler *sched); int cpu_disable_scheduler(unsigned int cpu); int schedule_cpu_add(unsigned int cpu, struct cpupool *c); +struct cpu_rm_data *alloc_cpu_rm_data(unsigned int cpu); +void free_cpu_rm_data(struct cpu_rm_data *mem, unsigned int cpu); int schedule_cpu_rm(unsigned int cpu); int sched_move_domain(struct domain *d, struct cpupool *c); struct cpupool *cpupool_get_by_id(unsigned int poolid); -- generated by git-patchbot for /home/xen/git/xen.git#master
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