All of lore.kernel.org
 help / color / mirror / Atom feed
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
Date: Tue, 13 Mar 2018 22:12:49 -0600	[thread overview]
Message-ID: <20180314041249.GA18314@ziepe.ca> (raw)
In-Reply-To: <1520997629-17361-3-git-send-email-okaya@codeaurora.org>

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

WARNING: multiple messages have this Message-ID (diff)
From: jgg@ziepe.ca (Jason Gunthorpe)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/7] RDMA/qedr: eliminate duplicate barriers on weakly-ordered archs
Date: Tue, 13 Mar 2018 22:12:49 -0600	[thread overview]
Message-ID: <20180314041249.GA18314@ziepe.ca> (raw)
In-Reply-To: <1520997629-17361-3-git-send-email-okaya@codeaurora.org>

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

  reply	other threads:[~2018-03-14  4:12 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-14  3:20 [PATCH 1/7] i40e/i40evf: Eliminate duplicate barriers on weakly-ordered archs Sinan Kaya
2018-03-14  3:20 ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20 ` Sinan Kaya
2018-03-14  3:20 ` Sinan Kaya
2018-03-14  3:20 ` [PATCH 2/7] ixgbe: eliminate " Sinan Kaya
2018-03-14  3:20   ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-15  1:47   ` Alexander Duyck
2018-03-15  1:47     ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:47     ` Alexander Duyck
2018-03-14  3:20 ` [PATCH 3/7] RDMA/qedr: " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-14  4:12   ` Jason Gunthorpe [this message]
2018-03-14  4:12     ` Jason Gunthorpe
2018-03-14 12:06     ` okaya
2018-03-14 12:06       ` okaya at codeaurora.org
2018-03-15 22:23   ` Jason Gunthorpe
2018-03-15 22:23     ` Jason Gunthorpe
2018-03-14  3:20 ` [PATCH 4/7] igbvf: " Sinan Kaya
2018-03-14  3:20   ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-15  1:48   ` Alexander Duyck
2018-03-15  1:48     ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:48     ` Alexander Duyck
2018-03-14  3:20 ` [PATCH 5/7] igb: " Sinan Kaya
2018-03-14  3:20   ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-15  1:50   ` Alexander Duyck
2018-03-15  1:50     ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:50     ` Alexander Duyck
2018-03-14  3:20 ` [PATCH 6/7] e1000: " Sinan Kaya
2018-03-14  3:20   ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-15  1:41   ` Alexander Duyck
2018-03-15  1:41     ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:41     ` Alexander Duyck
2018-03-15 23:30     ` Sinan Kaya
2018-03-15 23:30       ` [Intel-wired-lan] " Sinan Kaya
2018-03-15 23:30       ` Sinan Kaya
2018-03-16  0:25       ` Alexander Duyck
2018-03-16  0:25         ` [Intel-wired-lan] " Alexander Duyck
2018-03-16  0:25         ` Alexander Duyck
2018-03-16  0:50         ` Sinan Kaya
2018-03-16  0:50           ` [Intel-wired-lan] " Sinan Kaya
2018-03-16  0:50           ` Sinan Kaya
2018-03-14  3:20 ` [PATCH 7/7] ixgbevf: " Sinan Kaya
2018-03-14  3:20   ` [Intel-wired-lan] " Sinan Kaya
2018-03-14  3:20   ` Sinan Kaya
2018-03-14  5:08   ` Timur Tabi
2018-03-14  5:08     ` [Intel-wired-lan] " Timur Tabi
2018-03-14  5:08     ` Timur Tabi
2018-03-14 12:13     ` okaya
2018-03-14 12:13       ` [Intel-wired-lan] " okaya
2018-03-14 12:13       ` okaya at codeaurora.org
2018-03-14 21:49       ` Alexander Duyck
2018-03-14 21:49         ` [Intel-wired-lan] " Alexander Duyck
2018-03-14 21:49         ` Alexander Duyck
2018-03-14 22:57         ` Sinan Kaya
2018-03-14 22:57           ` [Intel-wired-lan] " Sinan Kaya
2018-03-14 22:57           ` Sinan Kaya
2018-03-15  1:44           ` Alexander Duyck
2018-03-15  1:44             ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:44             ` Alexander Duyck
2018-03-15  2:17             ` Sinan Kaya
2018-03-15  2:17               ` [Intel-wired-lan] " Sinan Kaya
2018-03-15  2:17               ` Sinan Kaya
2018-03-15 14:32               ` Alexander Duyck
2018-03-15 14:32                 ` [Intel-wired-lan] " Alexander Duyck
2018-03-15 14:32                 ` Alexander Duyck
2018-03-15 16:21                 ` Sinan Kaya
2018-03-15 16:21                   ` [Intel-wired-lan] " Sinan Kaya
2018-03-15 16:21                   ` Sinan Kaya
2018-03-15 16:27                   ` Sinan Kaya
2018-03-15 16:27                     ` [Intel-wired-lan] " Sinan Kaya
2018-03-15 16:27                     ` Sinan Kaya
2018-03-15 16:58                     ` Alexander Duyck
2018-03-15 16:58                       ` [Intel-wired-lan] " Alexander Duyck
2018-03-15 16:58                       ` Alexander Duyck
2018-03-15  1:45   ` Alexander Duyck
2018-03-15  1:45     ` [Intel-wired-lan] " Alexander Duyck
2018-03-15  1:45     ` Alexander Duyck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180314041249.GA18314@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=Ariel.Elior@cavium.com \
    --cc=Michal.Kalderon@cavium.com \
    --cc=dledford@redhat.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=okaya@codeaurora.org \
    --cc=sulrich@codeaurora.org \
    --cc=timur@codeaurora.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.