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

Jason Gunthorpe jgg at ziepe.ca
Thu Mar 15 15:23:46 PDT 2018


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 at codeaurora.org>
> Acked-by: Jason Gunthorpe <jgg at mellanox.com>
>  drivers/infiniband/hw/qedr/verbs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Applied to RDMA for-next

Thanks,
Jason



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