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SubjectRe: The reason to call it 3.0 is the desktop (was Re: [OT] 2.6 not 3.0 - (NUMA))
Date
On Monday 07 October 2002 20:58, Chris Friesen wrote:
> Andrew Morton wrote:
>
> > Go into ext2_new_inode, replace the call to find_group_dir with
> > find_group_other. Then untar a kernel tree, unmount the fs,
> > remount it and see how long it takes to do a
> >
> > `find . -type f xargs cat > /dev/null'
> >
> > on that tree. If your disk is like my disk, you will achieve
> > full disk bandwidth.
>
> Pardon my ignorance, but what's the difference between find_group_dir
> and find_group_other, and why aren't we using find_group_other already
> if its so much faster?

These are the heuristics that determine where in the volume directory
inodes are allocated:

http://lxr.linux.no/source/fs/ext2/ialloc.c#L221

Ext2 likes to spread directory inodes around the volume so that there is
room to keep the associated file blocks nearby. This interacts rather
poorly with readahead.

--
Daniel
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