From: Andi Kleen <ak@suse.de>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, wfg@mail.ustc.edu.cn, mstone@mathom.us
Subject: Re: [PATCH 00/33] Adaptive read-ahead V12
Date: 26 May 2006 16:00:14 +0200 [thread overview]
Message-ID: <p73irns7uoh.fsf@bragg.suse.de> (raw)
In-Reply-To: <20060525084415.3a23e466.akpm@osdl.org>
Andrew Morton <akpm@osdl.org> writes:
>
> These are nice-looking numbers, but one wonders. If optimising readahead
> makes this much difference to postgresql performance then postgresql should
> be doing the readahead itself, rather than relying upon the kernel's
> ability to guess what the application will be doing in the future. Because
> surely the database can do a better job of that than the kernel.
With that argument we should remove all readahead from the kernel?
Because it's already trying to guess what the application will do.
I suspect it's better to have good readahead code in the kernel
than in a zillion application.
-Andi
next prev parent reply other threads:[~2006-05-26 14:00 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20060524111246.420010595@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 00/33] Adaptive read-ahead V12 Wu Fengguang
2006-05-25 15:44 ` Andrew Morton
2006-05-25 19:26 ` Michael Stone
2006-05-25 19:40 ` David Lang
2006-05-25 22:01 ` Andrew Morton
2006-05-25 20:28 ` David Lang
2006-05-26 0:48 ` Michael Stone
[not found] ` <20060526011939.GA6220@mail.ustc.edu.cn>
2006-05-26 1:19 ` Wu Fengguang
2006-05-26 2:10 ` Jon Smirl
2006-05-26 3:14 ` Nick Piggin
2006-05-26 14:00 ` Andi Kleen [this message]
2006-05-26 16:25 ` Andrew Morton
2006-05-26 23:54 ` Folkert van Heusden
2006-05-27 0:00 ` Con Kolivas
2006-05-27 0:08 ` Con Kolivas
2006-05-28 22:20 ` Diego Calleja
2006-05-28 22:31 ` kernel
[not found] ` <20060529030445.GB5994@mail.ustc.edu.cn>
2006-05-29 3:04 ` Wu Fengguang
[not found] ` <20060524111857.983845462@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 02/33] radixtree: look-aside cache Wu Fengguang
[not found] ` <20060524111858.357709745@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 03/33] radixtree: hole scanning functions Wu Fengguang
2006-05-25 16:19 ` Andrew Morton
[not found] ` <20060526070416.GB5135@mail.ustc.edu.cn>
2006-05-26 7:04 ` Wu Fengguang
[not found] ` <20060526110559.GA14398@mail.ustc.edu.cn>
2006-05-26 11:05 ` Wu Fengguang
2006-05-26 16:19 ` Andrew Morton
[not found] ` <20060524111859.540640819@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 05/33] readahead: refactor do_generic_mapping_read() Wu Fengguang
[not found] ` <20060524111859.909928820@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 06/33] readahead: refactor __do_page_cache_readahead() Wu Fengguang
2006-05-25 16:30 ` Andrew Morton
2006-05-25 22:33 ` Paul Mackerras
2006-05-25 22:40 ` Andrew Morton
[not found] ` <20060526071339.GE5135@mail.ustc.edu.cn>
2006-05-26 7:13 ` Wu Fengguang
[not found] ` <20060524111900.419314658@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 07/33] readahead: insert cond_resched() calls Wu Fengguang
[not found] ` <20060524111900.970898174@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 08/33] readahead: common macros Wu Fengguang
2006-05-25 5:56 ` Nick Piggin
[not found] ` <20060525104117.GE4996@mail.ustc.edu.cn>
2006-05-25 10:41 ` Wu Fengguang
2006-05-26 3:33 ` Nick Piggin
[not found] ` <20060526065906.GA5135@mail.ustc.edu.cn>
2006-05-26 6:59 ` Wu Fengguang
[not found] ` <20060525134224.GJ4996@mail.ustc.edu.cn>
2006-05-25 13:42 ` Wu Fengguang
2006-05-25 14:38 ` Andrew Morton
2006-05-25 16:33 ` Andrew Morton
[not found] ` <20060524111901.581603095@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 09/33] readahead: events accounting Wu Fengguang
2006-05-25 16:36 ` Andrew Morton
[not found] ` <20060526070943.GD5135@mail.ustc.edu.cn>
2006-05-26 7:09 ` Wu Fengguang
[not found] ` <20060527132002.GA4814@mail.ustc.edu.cn>
2006-05-27 13:20 ` Wu Fengguang
2006-05-29 8:19 ` Martin Peschke
[not found] ` <20060524111901.976888971@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 10/33] readahead: support functions Wu Fengguang
2006-05-25 5:13 ` Nick Piggin
[not found] ` <20060525111318.GH4996@mail.ustc.edu.cn>
2006-05-25 11:13 ` Wu Fengguang
2006-05-25 16:48 ` Andrew Morton
[not found] ` <20060526073114.GH5135@mail.ustc.edu.cn>
2006-05-26 7:31 ` Wu Fengguang
[not found] ` <20060524111902.491708692@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 11/33] readahead: sysctl parameters Wu Fengguang
2006-05-25 4:50 ` [PATCH 12/33] readahead: min/max sizes Nick Piggin
[not found] ` <20060525121206.GI4996@mail.ustc.edu.cn>
2006-05-25 12:12 ` Wu Fengguang
[not found] ` <20060524111903.510268987@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 13/33] readahead: state based method - aging accounting Wu Fengguang
2006-05-26 17:04 ` Andrew Morton
[not found] ` <20060527062234.GB4991@mail.ustc.edu.cn>
2006-05-27 6:22 ` Wu Fengguang
2006-05-27 7:00 ` Andrew Morton
[not found] ` <20060527072201.GA5284@mail.ustc.edu.cn>
2006-05-27 7:22 ` Wu Fengguang
[not found] ` <20060524111904.019763011@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 14/33] readahead: state based method - data structure Wu Fengguang
2006-05-25 6:03 ` Nick Piggin
[not found] ` <20060525104353.GF4996@mail.ustc.edu.cn>
2006-05-25 10:43 ` Wu Fengguang
2006-05-26 17:05 ` Andrew Morton
[not found] ` <20060527070248.GD4991@mail.ustc.edu.cn>
2006-05-27 7:02 ` Wu Fengguang
[not found] ` <20060527082758.GF4991@mail.ustc.edu.cn>
2006-05-27 8:27 ` Wu Fengguang
[not found] ` <20060524111904.683513683@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 15/33] readahead: state based method - routines Wu Fengguang
2006-05-26 17:15 ` Andrew Morton
[not found] ` <20060527020616.GA7418@mail.ustc.edu.cn>
2006-05-27 2:06 ` Wu Fengguang
[not found] ` <20060524111906.245276338@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 18/33] readahead: initial method - guiding sizes Wu Fengguang
[not found] ` <20060524111906.588647885@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 19/33] readahead: initial method - thrashing guard size Wu Fengguang
[not found] ` <20060524111907.134685550@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 20/33] readahead: initial method - expected read size Wu Fengguang
2006-05-25 5:34 ` [PATCH 22/33] readahead: initial method Nick Piggin
[not found] ` <20060525085957.GC4996@mail.ustc.edu.cn>
2006-05-25 8:59 ` Wu Fengguang
2006-05-26 17:29 ` [PATCH 20/33] readahead: initial method - expected read size Andrew Morton
[not found] ` <20060527063826.GC4991@mail.ustc.edu.cn>
2006-05-27 6:38 ` Wu Fengguang
[not found] ` <20060524111908.569533741@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 23/33] readahead: backward prefetching method Wu Fengguang
2006-05-26 17:37 ` Nate Diller
2006-05-26 19:22 ` Nathan Scott
[not found] ` <20060528123006.GC6478@mail.ustc.edu.cn>
2006-05-28 12:30 ` Wu Fengguang
[not found] ` <20060524111909.147416866@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 24/33] readahead: seeking reads method Wu Fengguang
[not found] ` <20060524111909.635589701@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 25/33] readahead: thrashing recovery method Wu Fengguang
[not found] ` <20060524111910.207894375@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 26/33] readahead: call scheme Wu Fengguang
[not found] ` <20060524111910.544274094@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 27/33] readahead: laptop mode Wu Fengguang
2006-05-26 17:38 ` Andrew Morton
[not found] ` <20060524111911.032100160@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 28/33] readahead: loop case Wu Fengguang
2006-05-24 14:01 ` Limin Wang
[not found] ` <20060525154846.GA6907@mail.ustc.edu.cn>
2006-05-25 15:48 ` wfg
[not found] ` <20060524111911.607080495@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 29/33] readahead: nfsd case Wu Fengguang
[not found] ` <20060524111912.156646847@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 30/33] readahead: turn on by default Wu Fengguang
[not found] ` <20060524111912.485160282@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 31/33] readahead: debug radix tree new functions Wu Fengguang
[not found] ` <20060524111912.967392912@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 32/33] readahead: debug traces showing accessed file names Wu Fengguang
[not found] ` <20060524111913.603476893@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 33/33] readahead: debug traces showing read patterns Wu Fengguang
[not found] ` <20060524111858.869793445@localhost.localdomain>
2006-05-24 11:12 ` [PATCH 04/33] readahead: page flag PG_readahead Wu Fengguang
2006-05-25 16:23 ` Andrew Morton
[not found] ` <20060526070646.GC5135@mail.ustc.edu.cn>
2006-05-26 7:06 ` Wu Fengguang
2006-05-24 12:27 ` Peter Zijlstra
[not found] ` <20060524123740.GA16304@mail.ustc.edu.cn>
2006-05-24 12:37 ` Wu Fengguang
2006-05-24 12:48 ` Peter Zijlstra
[not found] ` <20060524111905.586110688@localhost.localdomain>
2006-05-24 11:13 ` [PATCH 17/33] readahead: context based method Wu Fengguang
2006-05-25 5:26 ` Nick Piggin
[not found] ` <20060525080308.GB4996@mail.ustc.edu.cn>
2006-05-25 8:03 ` Wu Fengguang
2006-05-26 17:23 ` Andrew Morton
[not found] ` <20060527021252.GB7418@mail.ustc.edu.cn>
2006-05-27 2:12 ` Wu Fengguang
2006-05-26 17:27 ` Andrew Morton
[not found] ` <20060527080443.GE4991@mail.ustc.edu.cn>
2006-05-27 8:04 ` Wu Fengguang
2006-05-24 12:37 ` Peter Zijlstra
[not found] ` <20060524133353.GA16508@mail.ustc.edu.cn>
2006-05-24 13:33 ` Wu Fengguang
2006-05-24 15:53 ` Peter Zijlstra
[not found] ` <20060525012556.GA6111@mail.ustc.edu.cn>
2006-05-25 1:25 ` Wu Fengguang
2006-05-26 9:53 [PATCH 00/33] Adaptive read-ahead V12 Just Marc
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