On 7/19/22 1:02 AM, Jinke Han wrote:
> From: Jinke Han <hanjinke.666@xxxxxxxxxxxxx>
>
> In our test of iocost, we encounttered some list add/del corrutions of
encountered and corruptions
> inner_walk list in ioc_timer_fn.
>
> The reason can be descripted as follow:
described
> cpu 0 cpu 1
> ioc_qos_write ioc_qos_write
>
> ioc = q_to_ioc(bdev_get_queue(bdev));
> if (!ioc) {
> ioc = kzalloc(); ioc = q_to_ioc(bdev_get_queue(bdev));
> if (!ioc) {
> ioc = kzalloc();
> ...
> rq_qos_add(q, rqos);
> }
> ...
> rq_qos_add(q, rqos);
> ...
> }
>
> When the io.cost.qos file is written by two cpu concurrently, rq_qos may
two cpus
> be added to one disk twice. In that case, there will be two iocs enabled
> and running on one disk. They own different iocgs on their active list.
> In the ioc_timer_fn function, because of the iocgs from two ioc have the
> same root iocg, the root iocg's walk_list may be overwritten by each
> other and this lead to list add/del corrutions in building or destorying
leads to, corruptions, destroying.
Outside of the spelling and grammer which I typically just fix up while
applying, this one doesn't apply to for-5.20/block. Please check and
resend it.
--
Jens Axboe
