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From: hch@lst.de (Christoph Hellwig)
Subject: [PATCHv3 0/3] nvme: NUMA locality for fabrics
Date: Tue, 20 Nov 2018 10:41:40 +0100	[thread overview]
Message-ID: <20181120094140.GA7742@lst.de> (raw)
In-Reply-To: <cc741191-12f3-91b0-df93-b6239f482aeb@suse.de>

On Tue, Nov 20, 2018@07:12:47AM +0100, Hannes Reinecke wrote:
> Fully agreed here.
> It all comes down to the link latency.
> If the link latency is the main bottleneck multipathing will benefit from 
> round-robin (or any I/O scheduler, for that matter).

It still makes a lot more sense to try to have queues with an affinity
to a given path rather than doing round robin IFF you care about latency.

If you latency sucks anyway round robing makes sense.  But why do you
use nvme on such a horrible interconnect anyway?

> And this it not just relevant for 'legacy' hardware; I've seen a 
> performance benefit on a 32G FC setup, which is pretty much state of the 
> art currently.

Well, FC is legacy no matter which link speed.

  reply	other threads:[~2018-11-20  9:41 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-02  9:56 [PATCHv3 0/3] nvme: NUMA locality for fabrics Hannes Reinecke
2018-11-02  9:56 ` [PATCH 1/3] nvme: NUMA locality information " Hannes Reinecke
2018-11-08  9:22   ` Christoph Hellwig
2018-11-08  9:35     ` Hannes Reinecke
2018-11-02  9:56 ` [PATCH 2/3] nvme-multipath: Select paths based on NUMA locality Hannes Reinecke
2018-11-08  9:32   ` Christoph Hellwig
2018-11-02  9:56 ` [PATCH 3/3] nvme-multipath: automatic NUMA path balancing Hannes Reinecke
2018-11-08  9:36   ` Christoph Hellwig
2018-11-16  8:12 ` [PATCHv3 0/3] nvme: NUMA locality for fabrics Christoph Hellwig
2018-11-16  8:21   ` Hannes Reinecke
2018-11-16  8:23     ` Christoph Hellwig
2018-11-19 22:31       ` Sagi Grimberg
2018-11-20  6:12         ` Hannes Reinecke
2018-11-20  9:41           ` Christoph Hellwig [this message]
2018-11-20 15:47             ` Keith Busch
2018-11-20 19:27               ` James Smart
2018-11-21  8:36                 ` Christoph Hellwig
2018-11-20 16:21             ` Hannes Reinecke
2018-11-20 18:12             ` James Smart

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