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From: Tejun Heo <tj@kernel.org>
To: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com, Mikulas Patocka <mpatocka@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm
Date: Thu, 02 Sep 2010 12:24:03 +0200	[thread overview]
Message-ID: <4C7F7B43.9030602@kernel.org> (raw)
In-Reply-To: <20100902032246.GA31484@redhat.com>

Hello,

On 09/02/2010 05:22 AM, Mike Snitzer wrote:
>> But we can meet in the middle.  I've reordered the DM FLUSH+FUA patches
>> so that the more intrusive bio-based relaxed ordering patch is at the
>> very end.
>>
>> My hope was that the request-based deadlock I'm seeing would disappear
>> if that relaxed ordering patch wasn't applied.  Unfortunately, I still
>> see the hang.

I don't think it would make any difference.  AFAICS, the patch doesn't
touch anything requested based dm uses.

> Turns out I can reproduce the hang on a stock 2.6.36-rc3 (without _any_
> FLUSH+FUA patches)!

Hmmm... that's interesting.

> I'll try to pin-point the root cause but I think my test is somehow
> exposing a bug in my virt setup.
> 
> So this hang is definitely starting to look like a red herring.
> 
> Tejun,
> 
> This news should clear the way for you to re-post your patches.  I think
> it would be best if you reordered the DM patches like I did here in this
> series: http://people.redhat.com/msnitzer/patches/flush-fua/series
> 
> In particular, the dm-relax-ordering-of-bio-based-flush-implementation
> patch should go at the end.  I think it makes for a more logical
> evolution of the DM code.

Sure, I'll.  I still think having the queue kicking mechanism is a
good idea tho.  I'll integrate that into series, reorder and repost
it.

Thanks.

-- 
tejun

  reply	other threads:[~2010-09-02 10:24 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1283162296-13650-1-git-send-email-tj@kernel.org>
2010-08-30  9:58 ` [PATCH 1/5] block: make __blk_rq_prep_clone() copy most command flags Tejun Heo
2010-08-30  9:58 ` [PATCH 2/5] dm: implement REQ_FLUSH/FUA support for bio-based dm Tejun Heo
2010-09-01 13:43   ` Mike Snitzer
2010-09-01 13:50     ` Tejun Heo
2010-09-01 13:54       ` Mike Snitzer
2010-09-01 13:56         ` Tejun Heo
2010-08-30  9:58 ` [PATCH 3/5] dm: relax ordering of bio-based flush implementation Tejun Heo
2010-08-30  9:58 ` [PATCH 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm Tejun Heo
2010-08-30  9:58 ` [PATCH 5/5] block: remove the WRITE_BARRIER flag Tejun Heo
     [not found] ` <1283162296-13650-5-git-send-email-tj@kernel.org>
2010-08-30 13:28   ` [PATCH 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm Mike Snitzer
     [not found]   ` <20100830132836.GB5283@redhat.com>
2010-08-30 13:59     ` Tejun Heo
     [not found]     ` <4C7BB932.1070405@kernel.org>
2010-08-30 15:07       ` Tejun Heo
2010-08-30 15:42       ` [PATCH] block: initialize flush request with WRITE_FLUSH instead of REQ_FLUSH Tejun Heo
2010-08-30 15:45       ` [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm Tejun Heo
     [not found]       ` <4C7BC942.7070703@kernel.org>
2010-08-30 19:08         ` [PATCH " Mike Snitzer
     [not found]         ` <20100830190835.GA8458@redhat.com>
2010-08-30 21:28           ` Mike Snitzer
2010-08-31 10:29             ` Tejun Heo
2010-08-31 13:02               ` Mike Snitzer
2010-08-31 13:14                 ` Tejun Heo
     [not found]       ` <4C7BD202.4040700@kernel.org>
2010-08-30 19:18         ` [PATCH UPDATED " Mike Snitzer
     [not found]         ` <20100830194731.GA10702@redhat.com>
2010-09-01 10:31           ` Mikulas Patocka
2010-09-01 11:20             ` Tejun Heo
2010-09-01 12:12               ` Mikulas Patocka
2010-09-01 12:42                 ` Tejun Heo
2010-09-01 12:54                   ` Mike Snitzer
2010-09-01 15:20                 ` Mike Snitzer
2010-09-01 15:35                   ` Mikulas Patocka
2010-09-01 17:07                     ` Mike Snitzer
2010-09-01 18:59                       ` Mike Snitzer
2010-09-02  3:22                         ` Mike Snitzer
2010-09-02 10:24                           ` Tejun Heo [this message]
2010-09-02 15:11                             ` Mike Snitzer
2010-09-09 15:26                           ` [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm] Mike Snitzer
2010-09-09 15:44                             ` Ryan Harper
2010-09-09 15:57                               ` Mike Snitzer
2010-09-09 16:03                                 ` Ryan Harper
2010-09-09 17:55                                   ` Mike Snitzer
2010-09-09 18:35                                     ` Ryan Harper
2010-09-09 19:15                                       ` Mike Snitzer
2010-09-09 19:43                                         ` Mike Snitzer
2010-09-09 20:14                                           ` Mike Snitzer
2010-09-09 20:30                                             ` Ryan Harper
2010-09-09 21:00                                               ` [PATCH] virtio-blk: put request that was created to retrieve the device id Mike Snitzer
2010-09-09 21:15                                                 ` Christoph Hellwig
2010-09-17 14:58                                                   ` Ryan Harper
2010-09-21 21:00                                                     ` Christoph Hellwig
2010-10-08 16:06                                                       ` [2.6.36 REGRESSION] " Mike Snitzer
2010-10-09  1:41                                                 ` [PATCH] " Rusty Russell
     [not found] ` <1283162296-13650-4-git-send-email-tj@kernel.org>
2010-09-01 13:51   ` [PATCH 3/5] dm: relax ordering of bio-based flush implementation Mike Snitzer
2010-09-01 13:56     ` Tejun Heo

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