Re: [PATCH 1/1] RDMA/iwcm: Fix WARNING:at_kernel/workqueue.c:#check_flush_dependency

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2024/8/20 3:28, Bart Van Assche 写道:
> On 8/17/24 1:42 AM, Zhu Yanjun wrote:
>> When workqueue_flush is invoked, WQ_MEM_RECLAIM is checked to avoid
>> errors.
>
> This description is too brief and not entirely correct. In the
> description of this patch it should be explained that WQ_MEM_RECLAIM 
> must be set for workqueues that are flushed from a work item queued on
> a WQ_MEM_RECLAIM workqueue or from a memory reclaim context. Otherwise a
> deadlock can occur. From kernel/workqueue.c:

Yeah. I will make changes to the commit logs based on the above comments.

Thanks for your advice.

>
> /**
>  * check_flush_dependency - check for flush dependency sanity
>  * @target_wq: workqueue being flushed
>  * @target_work: work item being flushed (NULL for workqueue flushes)
>  *
>  * %current is trying to flush the whole @target_wq or @target_work on 
> it.
>  * If @target_wq doesn't have %WQ_MEM_RECLAIM, verify that %current is 
> not
>  * reclaiming memory or running on a workqueue which doesn't have
>  * %WQ_MEM_RECLAIM as that can break forward-progress guarantee 
> leading to
>  * a deadlock.
>  */
>
>> Reported-by: kernel test robot <oliver.sang@intel.com>
>> Closes: 
>> https://lore.kernel.org/oe-lkp/202408151633.fc01893c-oliver.sang@intel.com
>> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
>
> Since this is a fix, please include a "Fixes:" tag.

Got it. I will add a "Fixes:" tag.

Best Regards,

Zhu Yanjun

>
> Thanks,
>
> Bart.
>
-- 
Best Regards,
Yanjun.Zhu