Re: [PATCH 1/2] blk-mq: not embed .mq_kobj and ctx->kobj into queue instance

jianchao.wang
2018-11-16T06:11:19Z

On 11/16/18 11:28 AM, Ming Lei wrote:
...
>
> +struct blk_mq_kobj {
> + struct kobject kobj;
> +};
> +
> static void blk_mq_sysfs_release(struct kobject *kobj)
> {
> + struct blk_mq_kobj *mq_kobj = container_of(kobj, struct blk_mq_kobj,
> + kobj);
> + kfree(mq_kobj);
> +}
> +
...
>
> -void blk_mq_sysfs_init(struct request_queue *q)
> +int blk_mq_sysfs_init(struct request_queue *q)
> {
> struct blk_mq_ctx *ctx;
> int cpu;
> + struct blk_mq_kobj *mq_kobj;
> +
> + mq_kobj = kzalloc(sizeof(struct blk_mq_kobj), GFP_KERNEL);
> + if (!mq_kobj)
> + return -ENOMEM;
>
> - kobject_init(&q->mq_kobj, &blk_mq_ktype);
> + kobject_init(&mq_kobj->kobj, &blk_mq_ktype);
>
> for_each_possible_cpu(cpu) {
> - ctx = per_cpu_ptr(q->queue_ctx, cpu);
> + ctx = kzalloc_node(sizeof(*ctx), GFP_KERNEL, cpu_to_node(cpu));
> + if (!ctx)
> + goto fail;
> + *per_cpu_ptr(q->queue_ctx, cpu) = ctx;
> kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
> }
> + q->mq_kobj = &mq_kobj->kobj;
> + return 0;
> +
> + fail:
> + for_each_possible_cpu(cpu) {
> + ctx = *per_cpu_ptr(q->queue_ctx, cpu);
> + if (ctx)
> + kobject_put(&ctx->kobj);
> + }
> + kobject_put(&mq_kobj->kobj);
> + return -ENOMEM;
> }

blk_mq_kobj looks meaningless, why do we need it, or do I miss something ?
And maybe we should allocate ctx in blk_mq_init_allocated_queue.

Thanks
Jianchao