Messages in this thread |  | | Subject | Re: [PATCH v3 4/4] io_uring: add support for zone-append | From | Jens Axboe <> | Date | Sun, 5 Jul 2020 15:00:47 -0600 |
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On 7/5/20 12:47 PM, Kanchan Joshi wrote: > From: Selvakumar S <selvakuma.s1@samsung.com> > > For zone-append, block-layer will return zone-relative offset via ret2 > of ki_complete interface. Make changes to collect it, and send to > user-space using cqe->flags. > > Signed-off-by: Selvakumar S <selvakuma.s1@samsung.com> > Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> > Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com> > Signed-off-by: Javier Gonzalez <javier.gonz@samsung.com> > --- > fs/io_uring.c | 21 +++++++++++++++++++-- > 1 file changed, 19 insertions(+), 2 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 155f3d8..cbde4df 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -402,6 +402,8 @@ struct io_rw { > struct kiocb kiocb; > u64 addr; > u64 len; > + /* zone-relative offset for append, in sectors */ > + u32 append_offset; > };
I don't like this very much at all. As it stands, the first cacheline of io_kiocb is set aside for request-private data. io_rw is already exactly 64 bytes, which means that you're now growing io_rw beyond a cacheline and increasing the size of io_kiocb as a whole.
Maybe you can reuse io_rw->len for this, as that is only used on the submission side of things.
-- Jens Axboe
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