From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: Steve Wise
<swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>,
Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>,
Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>,
List Linux RDMA Mailing
<linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: NFSD generic R/W API (sendto path) performance results
Date: Thu, 17 Nov 2016 13:46:02 +0100 [thread overview]
Message-ID: <20161117124602.GA25821@lst.de> (raw)
In-Reply-To: <BA9DC9F7-C893-428B-AFE5-EFCCD13C9F25-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
On Wed, Nov 16, 2016 at 02:45:33PM -0500, Chuck Lever wrote:
> Out of curiosity, I hacked up my NFS client to limit the size of RDMA
> segments to 30 pages (the server HCA's max_sge).
>
> A 1MB NFS READ now takes 9 segments. That forces the after-conversion
> server to build single-Write chains and use 9 post_send calls to
> transmit the READ payload, just like the before-conversion server.
>
> Performance of before- and after-conversion servers is now equivalent.
>
> kB reclen write rewrite read reread
> 2097152 1024 1061237 1141614 1961410 2000223
What HCA is this, btw? Also did you try to always register for > max_sge
calls? The code can already register all segments with the
rdma_rw_force_mr module option, so it would only need a small tweak for
that behavior.
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next prev parent reply other threads:[~2016-11-17 12:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-15 18:45 NFSD generic R/W API (sendto path) performance results Chuck Lever
[not found] ` <9170C872-DEE1-4D96-B9D8-E9D2B3F91915-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-11-15 20:35 ` Steve Wise
2016-11-16 19:45 ` Chuck Lever
[not found] ` <BA9DC9F7-C893-428B-AFE5-EFCCD13C9F25-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-11-17 12:46 ` Christoph Hellwig [this message]
[not found] ` <20161117124602.GA25821-jcswGhMUV9g@public.gmane.org>
2016-11-17 15:04 ` Chuck Lever
[not found] ` <84B43CFF-EBF7-4758-8751-8C97102C5BCF-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-11-17 19:20 ` Chuck Lever
[not found] ` <676323E9-2F30-4DB0-AEF8-CDE38E8A0715-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-11-17 20:03 ` Steve Wise
2016-11-17 20:20 ` Chuck Lever
2016-11-17 20:20 ` Sagi Grimberg
[not found] ` <c6190e4c-9b8e-3937-ba38-7861eebeaaae-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2016-11-17 20:42 ` Chuck Lever
[not found] ` <EB5A41EB-53AB-4BC9-A5A3-893A9828A5C9-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-11-23 15:01 ` Chuck Lever
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