From: Long Li <longli@microsoft.com>
To: Steve French <smfrench@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Steve French <sfrench@samba.org>,
"linux-cifs@vger.kernel.org" <linux-cifs@vger.kernel.org>,
"samba-technical@lists.samba.org"
<samba-technical@lists.samba.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: RE: [RFC PATCH 09/09] Introduce cache=rdma moutning option
Date: Fri, 18 May 2018 20:58:08 +0000 [thread overview]
Message-ID: <MWHPR2101MB0729D163B903A0198A85AB4BCE900@MWHPR2101MB0729.namprd21.prod.outlook.com> (raw)
In-Reply-To: <CAH2r5mtzUJUakbPr_kzrDcqVPC9QuS7K8MXejNz7F=Uii6K5Kg@mail.gmail.com>
> Subject: Re: [RFC PATCH 09/09] Introduce cache=rdma moutning option
>
> On Fri, May 18, 2018 at 12:00 PM, Long Li via samba-technical <samba-
> technical@lists.samba.org> wrote:
> >> Subject: Re: [RFC PATCH 09/09] Introduce cache=rdma moutning option
> >>
> >> On Thu, May 17, 2018 at 05:22:14PM -0700, Long Li wrote:
> >> > From: Long Li <longli@microsoft.com>
> >> >
> >> > When cache=rdma is enabled on mount options, CIFS do not allocate
> >> > internal data buffer pages for I/O, data is read/writen directly to
> >> > user
> >> memory via RDMA.
> >>
> >> I don't think this should be an option. For direct I/O without
> >> signing or encryption CIFS should always use get_user_pages, with or
> without RDMA.
> >
> > Yes this should be done for all transport. If there are no objections, I'll send
> patches to change this.
>
> Would this help/change performance much?
On RDMA, it helps with I/O latency and reduces CPU usage on certain I/O patterns.
But I haven't tested on TCP. Maybe it will help a little bit.
>
>
>
> --
> Thanks,
>
> Steve
next prev parent reply other threads:[~2018-05-18 20:58 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 0:22 [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA Long Li
2018-05-17 23:10 ` Tom Talpey
2018-05-18 6:03 ` Long Li
2018-05-18 6:44 ` Christoph Hellwig
2018-05-19 0:58 ` Tom Talpey
2018-05-18 6:42 ` Christoph Hellwig
2018-05-18 0:22 ` [RFC PATCH 01/09] Introduce offset for the 1st page in data transfer structures Long Li
2018-05-18 6:37 ` Steve French
2018-05-18 0:22 ` [RFC PATCH 02/09] Change wdata alloc to support direct pages Long Li
2018-05-19 1:05 ` Tom Talpey
2018-05-18 0:22 ` [RFC PATCH 03/09] Change rdata " Long Li
2018-05-18 0:22 ` [RFC PATCH 04/09] Change function to support offset when reading pages Long Li
2018-05-18 0:22 ` [RFC PATCH 05/09] Change RDMA send to regonize page offset in the 1st page Long Li
2018-05-19 1:09 ` Tom Talpey
2018-05-19 5:54 ` Long Li
2018-05-18 0:22 ` [RFC PATCH 06/09] Change RDMA recv to support " Long Li
2018-05-18 0:22 ` [RFC PATCH 07/09] Support page offset in memory regsitrations Long Li
2018-05-18 0:22 ` [RFC PATCH 08/09] Implement direct file I/O interfaces Long Li
2018-05-18 0:22 ` [RFC PATCH 09/09] Introduce cache=rdma moutning option Long Li
2018-05-18 7:26 ` Christoph Hellwig
2018-05-18 19:00 ` Long Li
2018-05-18 20:44 ` Steve French
2018-05-18 20:58 ` Long Li [this message]
2018-05-19 1:20 ` Tom Talpey
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