From: Andrew Morton <akpm@linux-foundation.org>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>,
David Cohen <david.a.cohen@linux.intel.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Damien Ramonda <damien.ramonda@intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] mm readahead: Fix the readahead fail in case of empty numa node
Date: Wed, 4 Dec 2013 00:41:25 -0800 [thread overview]
Message-ID: <20131204004125.a06f7dfc.akpm@linux-foundation.org> (raw)
In-Reply-To: <529EE811.5050306@linux.vnet.ibm.com>
On Wed, 04 Dec 2013 14:00:09 +0530 Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> wrote:
> > I don't recall the rationale for the current code and of course we
> > didn't document it. It might be in the changelogs somewhere - could
> > you please do the git digging and see if you can find out?
>
> Unfaortunately, from my search, I saw that the code belonged to pre git
> time, so could not get much information on that.
Here: https://lkml.org/lkml/2004/8/20/242
It seems it was done as a rather thoughtless performance optimisation.
I'd say it's time to reimplement max_sane_readahead() from scratch.
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WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>,
David Cohen <david.a.cohen@linux.intel.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Damien Ramonda <damien.ramonda@intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] mm readahead: Fix the readahead fail in case of empty numa node
Date: Wed, 4 Dec 2013 00:41:25 -0800 [thread overview]
Message-ID: <20131204004125.a06f7dfc.akpm@linux-foundation.org> (raw)
In-Reply-To: <529EE811.5050306@linux.vnet.ibm.com>
On Wed, 04 Dec 2013 14:00:09 +0530 Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> wrote:
> > I don't recall the rationale for the current code and of course we
> > didn't document it. It might be in the changelogs somewhere - could
> > you please do the git digging and see if you can find out?
>
> Unfaortunately, from my search, I saw that the code belonged to pre git
> time, so could not get much information on that.
Here: https://lkml.org/lkml/2004/8/20/242
It seems it was done as a rather thoughtless performance optimisation.
I'd say it's time to reimplement max_sane_readahead() from scratch.
next prev parent reply other threads:[~2013-12-04 8:40 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-03 10:36 [PATCH RFC] mm readahead: Fix the readahead fail in case of empty numa node Raghavendra K T
2013-12-03 10:36 ` Raghavendra K T
2013-12-03 22:38 ` Andrew Morton
2013-12-03 22:38 ` Andrew Morton
2013-12-04 8:30 ` Raghavendra K T
2013-12-04 8:30 ` Raghavendra K T
2013-12-04 8:41 ` Andrew Morton [this message]
2013-12-04 8:41 ` Andrew Morton
2013-12-04 9:08 ` Raghavendra K T
2013-12-04 9:08 ` Raghavendra K T
2013-12-04 21:48 ` Andrew Morton
2013-12-04 21:48 ` Andrew Morton
2013-12-05 5:57 ` Raghavendra K T
2013-12-05 5:57 ` Raghavendra K T
2013-12-11 22:49 ` Jan Kara
2013-12-11 22:49 ` Jan Kara
2013-12-11 23:05 ` Andrew Morton
2013-12-11 23:05 ` Andrew Morton
2013-12-12 11:14 ` Jan Kara
2013-12-12 11:14 ` Jan Kara
2013-12-14 0:39 ` Linus Torvalds
2013-12-14 0:39 ` Linus Torvalds
2013-12-31 11:07 ` Raghavendra K T
2013-12-31 11:07 ` Raghavendra K T
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