Re: [PATCH v2 05/13] xen/pvcalls: implement bind command

From: Stefano Stabellini
Date: Mon Jul 31 2017 - 18:17:26 EST


On Thu, 27 Jul 2017, Boris Ostrovsky wrote:
> >> This all looks very similar to previous patches. Can it be factored out?
> > You are right that the pattern is the same for all commands:
> > - get a request
> > - fill the request
> > - possibly do something else
> > - wait
> > however each request is different, the struct and fields are different.
> > There are spin_lock and spin_unlock calls intermingled. I am not sure I
> > can factor out much of this. Maybe I could create a static inline or
> > macro as a syntactic sugar to replace the wait call, but that's pretty
> > much it I think.
>
> Maybe you could factor out common fragments, not necessarily the whole
> thing at once?
>
> For example,
>
> static inline int get_request(*bedata, int *req_id)
> {
>
> *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
> if (RING_FULL(&bedata->ring) ||
> READ_ONCE(bedata->rsp[*req_id].req_id) != PVCALLS_INVALID_ID) {
> return -EAGAIN;
> return 0;
> }
>
> (or some such)

You are right, the code looks better this way. I'll add it.