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Date: Tue, 13 Mar 2018 22:12:49 -0600
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Sinan Kaya <okaya@codeaurora.org>
Cc: netdev@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org,
        linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Michal Kalderon <Michal.Kalderon@cavium.com>,
        Ariel Elior <Ariel.Elior@cavium.com>,
        Doug Ledford <dledford@redhat.com>, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/7] RDMA/qedr: eliminate duplicate barriers on
 weakly-ordered archs
Message-ID: <20180314041249.GA18314@ziepe.ca>
References: <1520997629-17361-1-git-send-email-okaya@codeaurora.org>
 <1520997629-17361-3-git-send-email-okaya@codeaurora.org>
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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 <okaya@codeaurora.org>
>  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 <jgg@mellanox.com>

Thanks,
Jason