From: Chuck Lever <chuck.lever@oracle.com>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH] SUNRPC: Remove rpc_xprt::tsh_size
Date: Thu, 3 Jan 2019 16:35:00 -0500 [thread overview]
Message-ID: <1353EAC5-5BEE-461E-A11E-31F00FC7B946@oracle.com> (raw)
In-Reply-To: <076cce85045dbaab3ca40947b2599f96cff66b53.camel@hammerspace.com>
> On Jan 3, 2019, at 4:28 PM, Trond Myklebust <trondmy@hammerspace.com> wrote:
>
> On Thu, 2019-01-03 at 16:07 -0500, Chuck Lever wrote:
>>> On Jan 3, 2019, at 3:53 PM, Chuck Lever <chuck.lever@oracle.com>
>>> wrote:
>>>
>>>> On Jan 3, 2019, at 1:47 PM, Trond Myklebust <
>>>> trondmy@hammerspace.com> wrote:
>>>>
>>>> On Thu, 2019-01-03 at 13:29 -0500, Chuck Lever wrote:
>>>>> + reclen = req->rq_snd_buf.len;
>>>>> + marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
>>>>> reclen);
>>>>> + return kernel_sendmsg(transport->sock, &msg, &iov, 1,
>>>>> iov.iov_len);
>>>>
>>>> So what does this do for performance? I'd expect that adding
>>>> another
>>>> dive into the socket layer will come with penalties.
>>>
>>> NFSv3 on TCP, sec=sys, 56Gbs IBoIP, v4.20 + my v4.21 patches
>>> fio, 8KB random, 70% read, 30% write, 16 threads, iodepth=16
>>>
>>> Without this patch:
>>>
>>> read: IOPS=28.7k, BW=224MiB/s (235MB/s)(11.2GiB/51092msec)
>>> write: IOPS=12.3k, BW=96.3MiB/s (101MB/s)(4918MiB/51092msec)
>>>
>>> With this patch:
>>>
>>> read: IOPS=28.6k, BW=224MiB/s (235MB/s)(11.2GiB/51276msec)
>>> write: IOPS=12.3k, BW=95.8MiB/s (100MB/s)(4914MiB/51276msec)
>>>
>>> Seems like that's in the noise.
>>
>> Sigh. That's because it was the same kernel. Again, with feeling:
>>
>> 4.20.0-rc7-00048-g9274254:
>> read: IOPS=28.6k, BW=224MiB/s (235MB/s)(11.2GiB/51276msec)
>> write: IOPS=12.3k, BW=95.8MiB/s (100MB/s)(4914MiB/51276msec)
>>
>> 4.20.0-rc7-00049-ga4dea15:
>> read: IOPS=27.2k, BW=212MiB/s (223MB/s)(11.2GiB/53979msec)
>> write: IOPS=11.7k, BW=91.1MiB/s (95.5MB/s)(4917MiB/53979msec)
>>
>
> So about a 5% reduction in performance?
On this workload, yes.
Could send the record marker in xs_send_kvec with the head[0] iovec.
I'm going to try that next.
--
Chuck Lever
next prev parent reply other threads:[~2019-01-03 21:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-03 18:29 [PATCH] SUNRPC: Remove rpc_xprt::tsh_size Chuck Lever
2019-01-03 18:47 ` Trond Myklebust
2019-01-03 20:53 ` Chuck Lever
2019-01-03 21:07 ` Chuck Lever
2019-01-03 21:28 ` Trond Myklebust
2019-01-03 21:35 ` Chuck Lever [this message]
2019-01-03 22:49 ` Chuck Lever
2019-01-04 4:00 ` Trond Myklebust
2019-01-04 21:35 ` Chuck Lever
2019-01-04 22:44 ` Trond Myklebust
2019-01-10 17:13 ` Chuck Lever
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