From: Sagi Grimberg <sagi@grimberg.me>
To: Hannes Reinecke <hare@suse.de>,
mwilck@suse.com, Christoph Hellwig <hch@lst.de>,
Keith Busch <keith.busch@intel.com>
Cc: marting@netapp.com, linux-nvme@lists.infradead.org
Subject: Re: [PATCH 1/2] nvme: multipath: round-robin: fix logic for non-optimized paths
Date: Tue, 21 Jul 2020 10:19:57 -0700 [thread overview]
Message-ID: <c51e7fa1-2e89-e5e1-6962-bc16470afd59@grimberg.me> (raw)
In-Reply-To: <b2e59b6e-e71a-a9d8-c768-a4a052449cf6@suse.de>
>>> Handle the special case where we have exactly one optimized path,
>>> which we should keep using in this case. Also, use the next
>>> non-optimized path, not the last one.
>>
>> Not sure I understand, does this patch also use nonopt paths if we
>> have a single opt path?
>
> Indeed, the latter change should be removed from this patch.
Why should we even do this? we have a clear indication from the
controller on ns access. If we have a optimized path we should never
select any non-optimized path.
What if a non-optimized path has a 50x higher access latency? it's just
wrong to use this path...
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next prev parent reply other threads:[~2020-07-21 17:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-16 19:59 [PATCH 1/2] nvme: multipath: round-robin: fix logic for non-optimized paths mwilck
2020-07-16 19:59 ` [PATCH 2/2] nvme: multipath: round-robin: don't fall back to numa mwilck
2020-07-17 6:10 ` Hannes Reinecke
2020-07-17 6:08 ` [PATCH 1/2] nvme: multipath: round-robin: fix logic for non-optimized paths Hannes Reinecke
2020-07-20 19:51 ` Sagi Grimberg
2020-07-21 6:39 ` Hannes Reinecke
2020-07-21 17:19 ` Sagi Grimberg [this message]
2020-07-22 5:35 ` Hannes Reinecke
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