From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
devel@linuxdriverproject.org,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
"James E.J. Bottomley" <JBottomley@odin.com>,
Radim Kr??m???? <rkrcmar@redhat.com>
Subject: Re: [PATCH] storvsc: get rid of homegrown copy_{to,from}_bounce_buffer()
Date: Wed, 23 Sep 2015 13:32:58 +0200 [thread overview]
Message-ID: <87pp19gyl1.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20150922215310.GA29802@infradead.org> (Christoph Hellwig's message of "Tue, 22 Sep 2015 14:53:10 -0700")
Christoph Hellwig <hch@infradead.org> writes:
> On Tue, Sep 22, 2015 at 06:27:50PM +0200, Vitaly Kuznetsov wrote:
>> Storvsc driver needs to ensure there are no 'holes' in the presented
>> sg list (all segments in the middle of the list need to be of PAGE_SIZE).
>
> I think it should instead set a virt_boundary. That's what we added for
> the NVMe driver which has the same requirements, and Sagi recently also
> switched iSER to it after we ensured that flag is handled correctly by
> the SG_IO ioctl.
Wow,
I checked and blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE
- 1) seems to be solving the issue completely, no bounce buffer
required. I'll test more and send v2 with removing the rest.
--
Vitaly
prev parent reply other threads:[~2015-09-23 11:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-22 16:27 [PATCH] storvsc: get rid of homegrown copy_{to,from}_bounce_buffer() Vitaly Kuznetsov
2015-09-22 21:53 ` Christoph Hellwig
2015-09-23 11:32 ` Vitaly Kuznetsov [this message]
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=87pp19gyl1.fsf@vitty.brq.redhat.com \
--to=vkuznets@redhat.com \
--cc=JBottomley@odin.com \
--cc=devel@linuxdriverproject.org \
--cc=haiyangz@microsoft.com \
--cc=hch@infradead.org \
--cc=kys@microsoft.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=rkrcmar@redhat.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox