Subject: Re: namei caching of newly created files?
To: Thor Lancelot Simon <>
From: Steve Rumble <>
List: tech-kern
Date: 01/23/2005 13:32:37
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On Sat, Jan 22, 2005 at 07:44:19PM -0500, Thor Lancelot Simon wrote:
> On Sat, Jan 22, 2005 at 03:06:28PM -0800, Jason Thorpe wrote:
> > Might as well check it in, then?
> I dunno -- Gordon's approach seemed a lot better to me -- even if it
> would really give the benefit only for new filesystems.  I also wonder
> if its expanding hash wouldn't give better performance for the truly
> gigantic directories where this version of the dirhash code seems to
> fall down.

I'm sure that there are better solutions, but this particular one
has the benefits of not only existing in a form that is quickly
made ready for integration, but of also having been out in the wild
for several years. We can pull it out easily if a better solution
materialises somewhere down the line that obviates dirhash.

The performance drop with huge directories has me a bit confused,
but I'm more inclined to think that it's something I've missed
(or fudged) rather than a limitation of dirhash itself.

I'm going to commit what I have (it's disabled by default) and let=20
others take a look.


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