From: Jeff Layton <jeff.layton@primarydata.com>
Date: Thu, 4 Dec 2014 12:28:45 -0500
To: Shirley Ma <shirley.ma@oracle.com>
Cc: Jeff Layton <jeff.layton@primarydata.com>,
        Trond Myklebust <trond.myklebust@primarydata.com>,
        Tejun Heo <tj@kernel.org>, NeilBrown <neilb@suse.de>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        Linux Kernel mailing list <linux-kernel@vger.kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [RFC PATCH 00/14] nfsd/sunrpc: add support for a
 workqueue-based nfsd
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On Thu, 04 Dec 2014 09:17:17 -0800
Shirley Ma <shirley.ma@oracle.com> wrote:

> I am looking at how to reduce total RPC execution time in NFS/RDMA. mountstats output shows that RPC backlog wait is too long, but increasing the credit limit doesn't seem help. Would this patchset help reducing total RPC execution time? 
> 
> Shirley
> 

I'm not sure. It depends on why you're seeing a backlog.

So far, my testing still shows this to be slightly (~2%) slower than the
same setup running a threaded nfsd, but that could be different with a
NUMA server or faster disks.

Probably there is some more tuning to do here before this is quite
ready for prime-time. It may be worth testing in your environment
though if you have the time and ability to do so.

> On 12/04/2014 03:47 AM, Jeff Layton wrote:
> > I was using ftrace with the sunrpc:* and workqueue:* tracepoints, and
> > had a simple perl script to postprocess the trace info to figure out
> > average/min/max latency.


-- 
Jeff Layton <jlayton@primarydata.com>
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