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

[Jens Axboe <axboe@kernel.dk>]

On Apr 8, 2026, at 4:51 PM, Tal Zussman <tz2294@columbia.edu> wrote:
> 
> 
> 
>> On 4/8/26 3:51 PM, Jens Axboe wrote:
>>> On 4/8/26 12: 48 PM, Tal Zussman wrote: > On 3/25/26 4: 14 PM, Jens Axboe wrote:
>>> 
>>> Thanks! I'm going to give Dave's llist suggestion a shot on top of
>>> this as it seems like it'll simplify this nicely. Looks like that'll
>>> involve turning bio::bi_next into a union with a struct llist_node.
>> 
>> Since these lists can get long, I'd keep an eye on llist reversal
>> overhead there...
>> 
> 
> 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”.

— 
Jens Axboe