Subject: Re: [PATCH 3/7] RDMA/qedr: eliminate duplicate barriers on weakly-ordered archs

From: Jason Gunthorpe <[email-masked]>
Date: Tue, 13 Mar 2018 22:12:49 -0600

On Tue, Mar 13, 2018 at 11:20:24PM -0400, Sinan Kaya wrote:
> Code includes wmb() followed by writel() in multiple places. writel()
> already has a barrier on some architectures like arm64.
> 
> This ends up CPU observing two barriers back to back before executing the
> register write.
> 
> Since code already has an explicit barrier call, changing writel() to
> writel_relaxed().
> 
> Signed-off-by: Sinan Kaya <[email-masked]>
>  drivers/infiniband/hw/qedr/verbs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Sure matches my understanding of writel_relaxed

This is part of a series, should we take just this patch through the
rdma tree? If not:

Acked-by: Jason Gunthorpe <[email-masked]>

Thanks,
Jason