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From: Vladislav Bolkhovitin <vst@vlnb.net>
To: Howard Chu <hyc@symas.com>
Cc: General Discussion of SQLite Database <sqlite-users@sqlite.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Vladislav Bolkhovitin <vst@vlnb.net>,
	"Theodore Ts'o" <tytso@mit.edu>,
	drh@hwaci.com, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [sqlite] light weight write barriers
Date: Mon, 12 Nov 2012 22:37:39 -0500	[thread overview]
Message-ID: <50A1C083.6080904@vlnb.net> (raw)
In-Reply-To: <50931601.4060102@symas.com>


Howard Chu, on 11/01/2012 08:38 PM wrote:
> Alan Cox wrote:
>>> How about that recently preliminary infrastructure to send ORDERED commands
>>> instead of queue draining was deleted from the kernel, because "there's no
>>> difference where to drain the queue, on the kernel or the storage side"?
>>
>> Send patches.
>
> Isn't any type of kernel-side ordering an exercise in futility, since
> a) the kernel has no knowledge of the disk's actual geometry
> b) most drives will internally re-order requests anyway
> c) cheap drives won't support barriers

This is why it is so important for performance to use all storage capabilities. 
Particularly, ORDERED commands instead of trying to pretend be smarter, than the 
storage, doing queue draining.

Vlad

  parent reply	other threads:[~2012-11-13  3:37 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CALwJ=MzHjAOs4J4kGH6HLdwP8E88StDWyAPVumNg9zCWpS9Tdg@mail.gmail.com>
2012-10-10 17:17 ` Andi Kleen
2012-10-11 16:32   ` [sqlite] " 杨苏立 Yang Su Li
2012-10-11 17:41     ` Christoph Hellwig
2012-10-23 19:53     ` Vladislav Bolkhovitin
2012-10-24 21:17       ` Nico Williams
2012-10-24 22:03         ` david
2012-10-25  0:20           ` Nico Williams
2012-10-25  1:04             ` david
2012-10-25  5:18               ` Nico Williams
2012-10-25  6:02                 ` Theodore Ts'o
2012-10-25  6:58                   ` david
2012-10-25 14:03                     ` Theodore Ts'o
2012-10-25 18:03                       ` david
2012-10-25 18:29                         ` Theodore Ts'o
2012-11-05 20:03                           ` Pavel Machek
2012-11-05 22:04                             ` Theodore Ts'o
     [not found]                               ` <CALwJ=Mx-uEFLXK2wywekk=0dwrwVFb68wocnH9bjXJmHRsJx3w@mail.gmail.com>
2012-11-05 23:00                                 ` Theodore Ts'o
2012-10-30 23:49                   ` Nico Williams
2012-10-25  5:42           ` Theodore Ts'o
2012-10-25  7:11             ` david
2012-10-27  1:52         ` Vladislav Bolkhovitin
2012-10-25  5:14       ` Theodore Ts'o
2012-10-25 13:03         ` Alan Cox
2012-10-25 13:50           ` Theodore Ts'o
2012-10-27  1:55             ` Vladislav Bolkhovitin
2012-10-27  1:54         ` Vladislav Bolkhovitin
2012-10-27  4:44           ` Theodore Ts'o
2012-10-30 22:22             ` Vladislav Bolkhovitin
2012-10-31  9:54               ` Alan Cox
2012-11-01 20:18                 ` Vladislav Bolkhovitin
2012-11-01 21:24                   ` Alan Cox
2012-11-02  0:15                     ` Vladislav Bolkhovitin
2012-11-02  0:38                     ` Howard Chu
2012-11-02 12:33                       ` Alan Cox
2012-11-13  3:41                         ` Vladislav Bolkhovitin
2012-11-13 17:40                           ` Alan Cox
2012-11-13 19:13                             ` Nico Williams
2012-11-15  1:17                               ` Vladislav Bolkhovitin
2012-11-15 12:07                                 ` David Lang
2012-11-16 15:06                                   ` Howard Chu
2012-11-16 15:31                                     ` Ric Wheeler
2012-11-16 15:54                                       ` Howard Chu
2012-11-16 18:03                                         ` Ric Wheeler
2012-11-16 19:14                                     ` David Lang
2012-11-17  5:02                                   ` Vladislav Bolkhovitin
     [not found]                                   ` <CABK4GYNGrbes2Yhig4ioh-37OXg6iy6gqb3u8A2P2_dqNpMqoQ@mail.gmail.com>
2012-11-17  5:02                                     ` Vladislav Bolkhovitin
2012-11-15 17:06                                 ` Ryan Johnson
2012-11-15 22:35                                   ` Chris Friesen
2012-11-17  5:02                                     ` Vladislav Bolkhovitin
2012-11-20  1:23                                       ` Vladislav Bolkhovitin
2012-11-26 20:05                                         ` Nico Williams
2012-11-29  2:15                                           ` Vladislav Bolkhovitin
2012-11-15  1:16                             ` Vladislav Bolkhovitin
2012-11-13  3:37                       ` Vladislav Bolkhovitin [this message]
     [not found]                       ` <CALwJ=MwtFAz7uby+YzPPp2eBG-y+TUTOu9E9tEJbygDQW+s_tg@mail.gmail.com>
2012-11-13  3:41                         ` Vladislav Bolkhovitin
     [not found]           ` <CABK4GYMmigmi7YM9A5Aga21ZWoMKgUe3eX-AhPzLw9CnYhpcGA@mail.gmail.com>
2012-11-13  3:42             ` Vladislav Bolkhovitin
     [not found]   ` <CALwJ=MyR+nU3zqi3V3JMuEGNwd8FUsw9xLACJvd0HoBv3kRi0w@mail.gmail.com>
2012-10-11 16:38     ` Nico Williams
2012-10-11 16:48       ` Nico Williams

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