Re: [PATCH RFC v4 1/3] block: add BIO_COMPLETE_IN_TASK for task-context completion

[Tal Zussman]

On 4/9/26 8:46 PM, Jens Axboe wrote:
> On 4/9/26 12:54 PM, Tal Zussman wrote:
>> On 4/8/26 7:36 PM, Jens Axboe wrote:
>>> On Apr 8, 2026, at 4:51PM, Tal Zussman <tz2294@xxxxxxxxxxxx> wrote:
>>>>
>>>> Going to send v5 shortly -- tested with and without the llist reversal and
>>>> it didn't seem to make much of a difference. This was on a single-disk VM
>>>> though, so any stress testing you could do would be very helpful.
>>>>
>>>
>>> With all due respect, a single test like that isn?t going to be that useful. I'd be wary of making that change willy nilly and just thinking it's fine, worked fine on the one case I tested?.
>> 
>> Understood -- unfortunately that's what I have access to at the moment. I
>> can requisition a machine with 2, maybe 3 disks, and test more thoroughly on
>> that before sending the next version, but that'll take a few days. You had
>> previously offered to test on your big box, so was hoping that was still on
>> the table :)
> 
> I can do that, but I'm OOO for the next week, so won't be until I'm
> back.
> 

No problem, thanks!

>> (Although Christoph seems to have proposed moving away from llist again)
> 
> I think that's a good idea, not a fan of using llist for this, in case
> that wasn't clear. These are per-cpu lists anyway, and having a constant
> overhead is better than needing to reverse an llist. IMHO.

Will change it back for the next version.

> -- 
> Jens Axboe
>