On Mon, Sep 24, 2012 at 03:34:44PM -0700, Kent Overstreet wrote:
> Converts it to use bio_advance(), simplifying it quite a bit in the
> process.
>
> Note that req_bio_endio() now always calls bio_advance() - which means
> it always loops over the biovec, not just on partial completions. Don't
> expect it to affect performance, but worth noting.
>
> Tested it by forcing partial updates, and dumping before and after on
> various bio/bvec fields when doing a partial update.
Kent,
In general, have you tested all these changes with FLUSH and DISCARD
bios/requests. Some of the code paths tend to break down because of these
special bios don't have payload.
Thanks
Vivek
On Tue, Oct 02, 2012 at 02:59:55PM -0400, Vivek Goyal wrote:
> On Mon, Sep 24, 2012 at 03:34:44PM -0700, Kent Overstreet wrote:
> > Converts it to use bio_advance(), simplifying it quite a bit in the
> > process.
> >
> > Note that req_bio_endio() now always calls bio_advance() - which means
> > it always loops over the biovec, not just on partial completions. Don't
> > expect it to affect performance, but worth noting.
> >
> > Tested it by forcing partial updates, and dumping before and after on
> > various bio/bvec fields when doing a partial update.
>
> Kent,
>
> In general, have you tested all these changes with FLUSH and DISCARD
> bios/requests. Some of the code paths tend to break down because of these
> special bios don't have payload.
Believe so, I should double check - also, I changed the bio_advance()
patch since the one I posted to make it handle DISCARD and WRITE_SAME
requests more explicitly.
(At this level, discards do (sometimes) have payloads, it's just always
a single page)