Re: [PATCH v4 2/2] block: Ensure that a request queue is dissociated from the cgroup controller

On 8/8/18 9:04 AM, Bart Van Assche wrote:

On Wed, 2018-08-08 at 08:41 -0600, Jens Axboe wrote:

...

On 7/30/18 3:10 PM, Bart Van Assche wrote:

...

+#ifdef CONFIG_BLK_CGROUP

• {

• struct blkcg_gq *blkg;
  

• rcu_read_lock();
  

• blkg = blkg_lookup(&blkcg_root, q);
  

• rcu_read_unlock();
  

• WARN(blkg,
  

•      "request queue %p is being released but it has not yet been removed from the blkcg controller\n",
  

•      q);
  

• }

+#endif

This last hunk should go in the cgroup code.

Hello Jens,

How about leaving out the #ifdef CONFIG_BLK_CGROUP / #endif? Would that be sufficient? I just noticed that blkg_lookup() returns NULL anyway if cgroup support is disabled in the kernel config.

That's even better.