Re: fuse scalability part 1

From: Srinivas Eeda <srinivas.eeda@oracle.com>
To: Miklos Szeredi <miklos@szeredi.hu>,
	Ashish Samant <ashish.samant@oracle.com>
Cc: Linux-Fsdevel <linux-fsdevel@vger.kernel.org>,
	Kernel Mailing List <linux-kernel@vger.kernel.org>,
	fuse-devel <fuse-devel@lists.sourceforge.net>
Subject: Re: fuse scalability part 1
Date: Mon, 28 Sep 2015 23:18:23 -0700	[thread overview]
Message-ID: <560A2D2F.2040609@oracle.com> (raw)
In-Reply-To: <CAJfpegsgjV2ePkdjZDAi5GoJ5M-Zeoy10v-5p+bzyHVAnGQpuA@mail.gmail.com>

Hi Miklos,

On 09/25/2015 05:11 AM, Miklos Szeredi wrote:
> On Thu, Sep 24, 2015 at 9:17 PM, Ashish Samant <ashish.samant@oracle.com> wrote:
>
>> We did some performance testing without these patches and with these patches
>> (with -o clone_fd  option specified). We did 2 types of tests:
>>
>> 1. Throughput test : We did some parallel dd tests to read/write to FUSE
>> based database fs on a system with 8 numa nodes and 288 cpus. The
>> performance here is almost equal to the the per-numa patches we submitted a
>> while back.Please find results attached.
> Interesting.  This means, that serving the request on a different NUMA
> node as the one where the request originated doesn't appear to make
> the performance much worse.
with the new change, contention of spinlock is significantly reduced, 
hence the latency caused by NUMA is not visible. Even in earlier case, 
the scalability was not a big problem if we bind all processes(fuse 
worker and user (dd threads)) to a single NUMA node. The problem was 
only seen when threads spread out across numa nodes and contend for the 
spin lock.

>
> Thanks,
> Miklos