Weirdness with discard cmd and get log pages

Keith Busch keith.busch at
Thu Oct 13 16:18:09 PDT 2016

On Thu, Oct 13, 2016 at 11:18:43AM -0700, Nisha Miller wrote:
> Yes, that is what I noticed too. I used the nvme-cli command like this:
> nvme dsm /dev/nvme0n1 -a 0,0,0,0 --blocks=4,5,6,7 --slbs=100,200,300,400 --ad
> This turns up as nvme_user_cmd in the driver, which calls
> nvme_map_user_pages to setup the SG list.

Okay, that's what I use too. I'm not observing any issues on a 4.8 kernel
or back to 4.4 either. I've not tested 3.19 though, and the mechanism
it uses to map user buffers is completely different. Could you verify if
your observation exists in a more current stable release?

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