Re: [PATCH v3 0/4] fast poll multishot mode

[Hao Xu]

在 2022/5/7 下午11:28, Jens Axboe 写道:
> On 5/7/22 8:06 AM, Hao Xu wrote:
> > Let multishot support multishot mode, currently only add accept as its
> > first comsumer.
>
> consumer
>
> > theoretical analysis:
> >    1) when connections come in fast
> >      - singleshot:
> >                add accept sqe(userpsace) --> accept inline
>
> userspace
>
> >                                ^                 |
> >                                |-----------------|
> >      - multishot:
> >               add accept sqe(userspace) --> accept inline
> >                                                ^     |
> >                                                |--*--|
> >
> >      we do accept repeatedly in * place until get EAGAIN
> >
> >    2) when connections come in at a low pressure
> >      similar thing like 1), we reduce a lot of userspace-kernel context
> >      switch and useless vfs_poll()
>
> Overall this looks better than v2 for sure, just some minor tweaks
> needed I believe.
>
> But we still need to consider direct accept with multishot... Should
> probably be an add-on patch as I think it'd get a bit more complicated
> if we need to be able to cheaply find an available free fixed fd slot.
> I'll try and play with that.

I'm tending to use a new mail account to send v4 rather than the gmail
account since the git issue seems to be network related.
I'll also think about the fixed fd problem.

Thanks,
Hao

>