Re: [PATCHv2 for-next 1/3] RDMA/rtrs-clt: Print more info when an error happens

[Jinpu Wang <jinpu.wang@ionos.com>]

On Tue, Apr 6, 2021 at 2:41 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Tue, Apr 06, 2021 at 02:36:37PM +0200, Gioh Kim wrote:
> > From: Gioh Kim <gi-oh.kim@cloud.ionos.com>
> >
> > Client prints only error value and it is not enough for debugging.
> >
> > 1. When client receives an error from server:
> > the client does not only print the error value but also
> > more information of server connection.
> >
> > 2. When client failes to send IO:
> > the client gets an error from RDMA layer. It also
> > print more information of server connection.
> >
> > Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
> > Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
> > ---
> >  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 33 ++++++++++++++++++++++----
> >  1 file changed, 29 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > index 5062328ac577..a534b2b09e13 100644
> > --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > @@ -437,6 +437,11 @@ static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
> >       req->in_use = false;
> >       req->con = NULL;
> >
> > +     if (unlikely(errno)) {
>
> I'm sorry, but all your patches are full of these likely/unlikely cargo
> cult. Can you please provide supportive performance data or delete all
> likely/unlikely in all rtrs code?

Hi Leon,

All the likely/unlikely from the non-fast path was removed as you
suggested in the past.
This one is on IO path, my understanding is for the fast path, with
likely/unlikely macro,
the compiler will optimize the code for better branch prediction.

We will run some benchmarks to see if it makes a difference.

Thanks
>
> Thanks