Re: [PATCH v3 00/12] io-uring/btrfs: support async buffered writes

David Sterba
2022-09-21T10:25:41Z

On Tue, Sep 20, 2022 at 02:25:40PM +0200, David Sterba wrote:
> On Mon, Sep 12, 2022 at 12:27:40PM -0700, Stefan Roesch wrote:
> > This patch series adds support for async buffered writes when using both
> > btrfs and io-uring. Currently io-uring only supports buffered writes (for btrfs)
> > in the slow path, by processing them in the io workers. With this patch series
> > it is now possible to support buffered writes in the fast path. To be able to use
> > the fast path, the required pages must be in the page cache, the required locks
> > in btrfs can be granted immediately and no additional blocks need to be read
> > form disk.
> >
> > This patch series makes use of the changes that have been introduced by a
> > previous patch series: "io-uring/xfs: support async buffered writes"
> >
> > Performance results:
> >
> > The new patch improves throughput by over two times (compared to the exiting
> > behavior, where buffered writes are processed by an io-worker process) and also
> > the latency is considerably reduced. Detailled results are part of the changelog
> > of the first commit.
>
> Thanks. It's late for including this patches to 6.1 queue but it's now
> in for-next and will be added to misc-next after rc1, targeting merge to
> 6.2. I did some minor fixups, so please don't resend full series unless
> there's a significant change. Incremental changes are fine if needed.

I'm revisiting the merge target, the potential risk seems to be low
here, straightforward changes for a separate feature, so it's now in the
6.1 queue. We still don't have ack for the function export so that would
be good to have.