dm-devel.redhat.com archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: dm-devel@redhat.com, Mike Snitzer <snitzer@redhat.com>
Subject: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm
Date: Wed, 01 Sep 2010 13:20:08 +0200	[thread overview]
Message-ID: <4C7E36E8.2000705@kernel.org> (raw)
In-Reply-To: <Pine.LNX.4.64.1009010625070.16035@hs20-bc2-1.build.redhat.com>

Hello,

On 09/01/2010 12:31 PM, Mikulas Patocka wrote:
> My recommended approach to this (on non-request-based dm) is to simply let 
> the current barrier infrastructure be as it is --- you don't need to 
> change it now, you can simply map FUA write to barrier write and FLUSH to 
> zero-data barrier --- and it won't cause any data corruption. It will just 
> force unneeded I/O queue draining.
> 
> Once FLUSH+FUA interface is finalized and committed upstream, we can 
> remove that I/O queue draining from dm to improve performance.

Unfortunately, it doesn't work that way.  The current dm
implementation depends on block layer holding the queue while a
barrier sequence is in progress which the new implementation doesn't
do anymore (the whole point of this conversion BTW).

Thanks.

-- 
tejun

  reply	other threads:[~2010-09-01 11:20 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 [this message]
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
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

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=4C7E36E8.2000705@kernel.org \
    --to=tj@kernel.org \
    --cc=dm-devel@redhat.com \
    --cc=mpatocka@redhat.com \
    --cc=snitzer@redhat.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;
as well as URLs for NNTP newsgroup(s).