From: "H. Peter Anvin" <hpa@zytor.com>
To: Andre Noll <maan@systemlinux.org>
Cc: Bill Davidsen <davidsen@tmr.com>,
Matti Aarnio <matti.aarnio@zmailer.org>,
Jesper Juhl <jj@chaosbits.net>,
Prakash Punnoor <prakash@punnoor.de>,
Michael Tokarev <mjt@tls.msk.ru>,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
neilb@suse.de
Subject: Re: Proposal: make RAID6 code optional
Date: Wed, 22 Apr 2009 11:39:19 -0700 [thread overview]
Message-ID: <49EF6457.90505@zytor.com> (raw)
In-Reply-To: <20090422180051.GD13280@skl-net.de>
Andre Noll wrote:
> On 10:23, H. Peter Anvin wrote:
>
>> We could use vmalloc() and generate the tables at initialization time.
>> However, having a separate module which exports the raid6 declaration
>> and uses the raid5 module as a subroutine library seems easier.
>
> Really? Easier than keeping only two 256-byte arrays for exp() and
> log() and use these at runtime to populate the (dynamically allocated)
> 64K GF multiplication table? That seems to be really simple and would
> still shave off 64K of kernel memory for raid5-only users.
>
Yes, I believe it would be easier than having dynamically allocated
arrays. Dynamically generated arrays using static memory allocations
(bss) is one thing, but that would only reduce size of the module on
disk, which I don't think anyone considers a problem.
-hpa
next prev parent reply other threads:[~2009-04-22 18:40 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-18 7:46 Proposal: make RAID6 code optional Prakash Punnoor
2009-04-18 8:09 ` Michael Tokarev
2009-04-18 9:16 ` Prakash Punnoor
2009-04-18 13:56 ` Jesper Juhl
2009-04-18 14:58 ` Matti Aarnio
2009-04-19 2:07 ` H. Peter Anvin
2009-04-19 2:27 ` NeilBrown
2009-04-19 6:28 ` Neil Brown
2009-04-21 13:58 ` Bill Davidsen
2009-04-21 17:23 ` H. Peter Anvin
2009-04-22 9:01 ` Goswin von Brederlow
2009-04-22 12:34 ` Bill Davidsen
2009-04-22 15:11 ` H. Peter Anvin
2009-04-22 18:00 ` Andre Noll
2009-04-22 18:31 ` Goswin von Brederlow
2009-04-22 18:50 ` Andre Noll
2009-04-22 18:39 ` H. Peter Anvin [this message]
2009-04-22 18:57 ` Andre Noll
2009-04-23 1:35 ` H. Peter Anvin
2009-04-23 8:07 ` Andre Noll
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