2003-02-13 03:21:02

by Peter Chubb

[permalink] [raw]
Subject: Re: [Ext2-devel] Re: fsck out of memory

>>>>> "Stephen" == Stephen C Tweedie <[email protected]> writes:

Stephen> Hi, On Tue, 2003-02-11 at 13:11, Stephan van Hienen wrote:

Stephen> I've no idea. Ben has some lb patches up at

Stephen> http://people.redhat.com/bcrl/lb/

Stephen> but there's nothing broken out against the latest lbd diffs.


Ben's patches are against a very old version of the kernel (2.4.6-pre8)
and require linking against libgcc to get 64-bit division.


The main issue is 64-bit division. In the limited time I had I
couldn't convince myself that I could rely on all divisors being less
than 2^31 in the raid4/5 code. If you can convince yourself of that,
then t's a straightforward but tedious task to make raid1, raid4 and
raid5 LBD-safe.

--
Dr Peter Chubb [email protected]
You are lost in a maze of BitKeeper repositories, all almost the same.


2003-02-13 03:52:28

by Randy.Dunlap

[permalink] [raw]
Subject: Re: [Ext2-devel] Re: fsck out of memory

>>>>>> "Stephen" == Stephen C Tweedie <[email protected]> writes:
>
> Stephen> Hi, On Tue, 2003-02-11 at 13:11, Stephan van Hienen wrote:
>
> Stephen> I've no idea. Ben has some lb patches up at
>
> Stephen> http://people.redhat.com/bcrl/lb/
>
> Stephen> but there's nothing broken out against the latest lbd diffs.
>
>
> Ben's patches are against a very old version of the kernel (2.4.6-pre8) and
> require linking against libgcc to get 64-bit division.
>
>
> The main issue is 64-bit division. In the limited time I had I
> couldn't convince myself that I could rely on all divisors being less than
> 2^31 in the raid4/5 code. If you can convince yourself of that, then t's a
> straightforward but tedious task to make raid1, raid4 and raid5 LBD-safe.
> --

Hi,
Is this in a speed-sensitive area?
If not, you could consider 64-bit software divide functions, such as found at
http://nemesis.sourceforge.net/browse/lib/static/intmath/ix86/intmath.c.html,
which would only be used on 32-bit CPUs, of course.

--
~Randy