From: keith.busch@linux.intel.com (Keith Busch)
Subject: [PATCH] nvme: use __GFP_NOWARN for iod allocation
Date: Wed, 20 Jun 2018 16:30:35 -0600 [thread overview]
Message-ID: <20180620223035.GA25196@localhost.localdomain> (raw)
In-Reply-To: <34e64832-c345-3a70-401f-1915b5bb4af1@kernel.dk>
On Wed, Jun 20, 2018@02:54:26PM -0600, Jens Axboe wrote:
> I should also mention that this came out of a real life hang
> on a production box. I suppose we haven't seen a lot of these
> since a lot of nvme controllers have a hw limit of 128k, but
> the ones that don't can pretty easily hit the hang of needing
> 2^2 pages and failing miserably forever.
I can certainly believe that. I'm totally fine with setting a smaller
upper bound on the IO size. There really isn't a meaningful bandwidth
advantage to larger transfers on NVMe PCIe once you get over 256k anyway.
Since you're making the change to core, let's wait to hear if there are
any concerns on the fabrics front.
next prev parent reply other threads:[~2018-06-20 22:30 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-20 19:10 [PATCH] nvme: use __GFP_NOWARN for iod allocation Jens Axboe
2018-06-20 19:16 ` Jens Axboe
2018-06-20 20:09 ` Jens Axboe
2018-06-20 20:43 ` Keith Busch
2018-06-20 20:54 ` Jens Axboe
2018-06-20 22:30 ` Keith Busch [this message]
2018-06-20 22:30 ` Jens Axboe
2018-06-21 7:10 ` Christoph Hellwig
2018-06-21 14:47 ` Jens Axboe
2018-06-21 15:01 ` Christoph Hellwig
2018-06-21 15:04 ` Jens Axboe
2018-06-21 15:06 ` Jens Axboe
2018-06-21 15:24 ` Christoph Hellwig
2018-06-21 15:26 ` Jens Axboe
2018-06-21 15:24 ` Christoph Hellwig
2018-06-21 15:34 ` Jens Axboe
2018-06-21 15:45 ` Christoph Hellwig
2018-06-21 15:49 ` Jens Axboe
2018-06-21 16:27 ` Keith Busch
2018-06-21 17:20 ` Jens Axboe
2018-06-21 17:54 ` Christoph Hellwig
2018-06-21 19:18 ` Jens Axboe
2018-06-20 20:51 ` Jens Axboe
2018-06-21 7:15 ` Christoph Hellwig
2018-06-21 14:37 ` Jens Axboe
2018-06-21 14:56 ` Christoph Hellwig
2018-06-21 15:01 ` Jens Axboe
2018-06-21 7:09 ` Christoph Hellwig
2018-06-21 14:39 ` Jens Axboe
2018-06-21 14:58 ` Christoph Hellwig
2018-06-21 15:02 ` Jens Axboe
2018-06-21 15:06 ` Christoph Hellwig
2018-06-21 15:11 ` Jens Axboe
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