Am 27.10.2021 um 11:23 hat Stefano Garzarella geschrieben:
On Wed, Oct 27, 2021 at 06:28:51AM +0200, Markus Armbruster wrote:
> Stefano Garzarella <sgarzare@redhat.com> writes:
>
> > Commit d7ddd0a161 ("linux-aio: limit the batch size using
> > `aio-max-batch` parameter") added a way to limit the batch size
> > of Linux AIO backend for the entire AIO context.
> >
> > The same AIO context can be shared by multiple devices, so
> > latency-sensitive devices may want to limit the batch size even
> > more to avoid increasing latency.
> >
> > For this reason we add the `aio-max-batch` option to the file
> > backend, which will be used by the next commits to limit the size of
> > batches including requests generated by this device.
> >
> > Suggested-by: Kevin Wolf <kwolf@redhat.com>
> > Reviewed-by: Kevin Wolf <kwolf@redhat.com>
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > ---
> >
> > Notes:
> > v2:
> > - @aio-max-batch documentation rewrite [Stefan, Kevin]
> >
> > qapi/block-core.json | 7 +++++++
> > block/file-posix.c | 9 +++++++++
> > 2 files changed, 16 insertions(+)
> >
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 6d3217abb6..fef76b0ea2 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -2896,6 +2896,12 @@
> > # for this device (default: none, forward the commands via
SG_IO;
> > # since 2.11)
> > # @aio: AIO backend (default: threads) (since: 2.8)
> > +# @aio-max-batch: maximum number of requests to batch together into a
single
> > +# submission in the AIO backend. The smallest value between
> > +# this and the aio-max-batch value of the IOThread object
is
> > +# chosen.
> > +# 0 means that the AIO backend will handle it
automatically.
> > +# (default: 0, since 6.2)
>
> "(default 0) (since 6.2)" seems to be more common.
Indeed I wasn't sure, so I followed @drop-cache, the last one added in
@BlockdevOptionsFile.
Actually, I think your style is more common, both globally and in
block-*:
$ git grep -i '[,;] since' qapi/ | wc -l
17
$ git grep -i '[,;] since' qapi/block* | wc -l
12
Compared to:
$ git grep -i ') (since' qapi/ | wc -l
14
$ git grep -i ') (since' qapi/block* | wc -l
7