Linux-NVME Archive on lore.kernel.org
 help / color / Atom feed
From: Keith Busch <kbusch@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>, linux-nvme@lists.infradead.org
Subject: Re: [PATCH] nvme: set dma alignment to qword
Date: Thu, 21 May 2020 08:41:51 -0700
Message-ID: <20200521154151.GB3269657@dhcp-10-100-145-180.wdl.wdc.com> (raw)
In-Reply-To: <20200521152929.GA18535@lst.de>

On Thu, May 21, 2020 at 05:29:29PM +0200, Christoph Hellwig wrote:
> On Thu, May 21, 2020 at 08:28:20AM -0700, Keith Busch wrote:
> > On Wed, May 20, 2020 at 11:05:51PM -0700, Sagi Grimberg wrote:
> > > 
> > > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> > > > index 805d289e6cd9..ba860efd250d 100644
> > > > --- a/drivers/nvme/host/core.c
> > > > +++ b/drivers/nvme/host/core.c
> > > > @@ -2283,6 +2283,7 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
> > > >   		blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX));
> > > >   	}
> > > >   	blk_queue_virt_boundary(q, ctrl->page_size - 1);
> > > > +	blk_queue_dma_alignment(q, 7);
> > > 
> > > Shouldn't be an issue for rdma/tcp, think that it should also be OK for
> > > FC as well but not sure.
> > 
> > Okay, just to be safe, I'll make this a nvme_ctrl_ops callback.
> 
> No callbacks please, especially without users.  If FC needs an override
> we should just add a field to struct nvme_ctrl.

Well, pci would be a user. But if you're okay with having the driver
default to this alignment, would you consider taking this original patch,
or do you want confirmation from FC developers on whether or not this
is safe?

_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

  reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21  2:22 Keith Busch
2020-05-21  6:05 ` Sagi Grimberg
2020-05-21 15:28   ` Keith Busch
2020-05-21 15:29     ` Christoph Hellwig
2020-05-21 15:41       ` Keith Busch [this message]
2020-05-21 15:42         ` Christoph Hellwig
2020-05-21 19:46           ` James Smart
2020-05-26 14:53 ` Christoph Hellwig

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=20200521154151.GB3269657@dhcp-10-100-145-180.wdl.wdc.com \
    --to=kbusch@kernel.org \
    --cc=hch@lst.de \
    --cc=linux-nvme@lists.infradead.org \
    --cc=sagi@grimberg.me \
    /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

Linux-NVME Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-nvme/0 linux-nvme/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-nvme linux-nvme/ https://lore.kernel.org/linux-nvme \
		linux-nvme@lists.infradead.org
	public-inbox-index linux-nvme

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-nvme


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git