From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Steve Wise" <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
Subject: RE: NFSoRDMA Fails for max_sge Less Than 18
Date: Fri, 13 Jan 2017 16:42:10 -0600
Message-ID: <062101d26dee$46e78df0$d4b6a9d0$@opengridcomputing.com>
References: <SN1PR07MB2207F28F05DC6E22B03CC516F8660@SN1PR07MB2207.namprd07.prod.outlook.com> <FE817A76-28A7-4AEC-AF1E-01DE15790E43@oracle.com> <027101d26c2c$c94467f0$5bcd37d0$@opengridcomputing.com> <28B0D906-7BDB-4B87-94E9-6BE263BFBFF7@oracle.com> <038901d26c44$67d6c4f0$37844ed0$@opengridcomputing.com> <383D1FFB-346B-40E9-A174-606F13AFF849@oracle.com> <03b301d26c47$f154a5a0$d3fdf0e0$@opengridcomputing.com> <A7A39994-66C6-4467-837B-288348C0CC53@oracle.com>
Mime-Version: 1.0
Content-Type: text/plain;
        charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
In-Reply-To: <A7A39994-66C6-4467-837B-288348C0CC53-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Content-Language: en-us
Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: 'Chuck Lever' <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: "'Amrani, Ram'" <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>, "'Elior, Ariel'" <Ariel.Elior-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>, "'Kalderon, Michal'" <Michal.Kalderon-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>, 'List Linux RDMA Mailing' <linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, 'Hariprasad S' <hariprasad-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>, 'Faisal Latif' <faisal.latif-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, 'Doug Ledford' <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
List-Id: linux-rdma@vger.kernel.org

> >>
> >>> (haven't looked in detail at your patches...sorry).  Our QA ran
testing on
> > 4.9
> >>> and didn't see this issue, so that's why I'm asking.    They have not
yet
> > run
> >>> NFS/RDMA testing on 4.9-rc.  I've asked them to do a quick regression
> test
> > asap.
> >>
> >
> > Correction: I meant 4.10-rc above.
> >
> > But still, I believe Chelsio tested 4.9, so perhaps it isn't the "mount"
that
> > causes a failure but trying to send something with an SGE > 4 that
happens
> > immediately after the mount?  And since cxgb4 supports up to 17, the
> failure
> > wouldn't be seen until some inline message was attempted that required
> 18
> > sges...
> 
> The original check for 18 or 19 was too aggressive (that's the
> bug here). With the default inline threshold settings, RPC-over-RDMA
> won't ever use more than 4 (or at most 5) SGEs for RDMA Send.
> 
> So if somehow the mount was allowed, and no changes were made to the
> default settings, everything should still work fine for cxgb4.
> 

Hey Chuck, Chelsio confirmed mounts fail with 4.10-rc.  So can you get a fix
in 4.10-rc (and back to 4.9 if the regression is there) to ensure at least a
max_sge of 4 is supported? 

Steveo


--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html