public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jens Axboe <axboe@fb.com>
To: Keith Busch <keith.busch@intel.com>
Cc: "Matias Bjørling" <m@bjorling.me>,
	"willy@linux.intel.com" <willy@linux.intel.com>,
	"sbradshaw@micron.com" <sbradshaw@micron.com>,
	"tom.leiming@gmail.com" <tom.leiming@gmail.com>,
	"hch@infradead.org" <hch@infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>
Subject: Re: [PATCH v7] NVMe: conversion to blk-mq
Date: Tue, 10 Jun 2014 15:14:35 -0600	[thread overview]
Message-ID: <5397753B.2020009@fb.com> (raw)
In-Reply-To: <alpine.LRH.2.03.1406101458470.4699@AMR>

On 06/10/2014 03:10 PM, Keith Busch wrote:
> On Tue, 10 Jun 2014, Jens Axboe wrote:
>> On 06/10/2014 01:29 PM, Keith Busch wrote:
>>> I have two devices, one formatted 4k, the other 512. The 4k is used as
>>> the TEST_DEV and 512 is used as SCRATCH_DEV. I'm always hitting a BUG
>>> when
>>> unmounting the scratch dev in xfstests generic/068. The bug looks like
>>> nvme was trying to use an SGL that doesn't map correctly to a PRP.
>>
>> I'm guessing it's some of the coalescing settings, since the driver is
>> now using the generic block rq mapping.
> 
> Ok, sounds right. I mentioned in a way earlier review it doesn't look
> like a request that doesn't conform to a PRP list would get split anymore,
> and this test seems to confirm that.
> 
> Can we create something that will allow a driver to add DMA constraints to
> a request queue with the rules of a PRP list?

I haven't even looked at the rules - can you briefly outline them? From
a quick look, seems it does prp chaining for every 512 entries. But
nvme_setup_prps() looks like voodoo to an uninitiated, it could have
used a comment or two :-)



  reply	other threads:[~2014-06-10 21:15 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-10  9:20 [PATCH v7] conversion to blk-mq Matias Bjørling
2014-06-10  9:20 ` [PATCH v7] NVMe: " Matias Bjørling
2014-06-10 15:51   ` Keith Busch
2014-06-10 16:19     ` Jens Axboe
2014-06-10 19:29       ` Keith Busch
2014-06-10 19:58         ` Jens Axboe
2014-06-10 21:10           ` Keith Busch
2014-06-10 21:14             ` Jens Axboe [this message]
2014-06-10 21:21               ` Keith Busch
2014-06-10 21:33                 ` Matthew Wilcox
2014-06-11 16:54                   ` Jens Axboe
2014-06-11 17:09                     ` Matthew Wilcox
2014-06-11 22:22                       ` Matias Bjørling
2014-06-11 22:51                         ` Keith Busch
2014-06-12 14:32                           ` Matias Bjørling
2014-06-12 16:24                             ` Keith Busch
2014-06-13  0:06                               ` Keith Busch
2014-06-13 14:07                                 ` Jens Axboe
2014-06-13 15:05                                   ` Keith Busch
2014-06-13 15:11                                     ` Jens Axboe
2014-06-13 15:16                                       ` Keith Busch
2014-06-13 18:14                                         ` Jens Axboe
2014-06-13 19:22                                           ` Keith Busch
2014-06-13 19:29                                             ` Jens Axboe
2014-06-13 20:56                                               ` Jens Axboe
2014-06-13 21:28                                             ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5397753B.2020009@fb.com \
    --to=axboe@fb.com \
    --cc=hch@infradead.org \
    --cc=keith.busch@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvme@lists.infradead.org \
    --cc=m@bjorling.me \
    --cc=sbradshaw@micron.com \
    --cc=tom.leiming@gmail.com \
    --cc=willy@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox