Re: [PATCH] dcache 2nd chance replacement

[Rik van Riel]

On Wed, 3 Jan 2001, Andrea Arcangeli wrote:
> On Wed, Jan 03, 2001 at 04:59:16PM -0200, Rik van Riel wrote:
> > I know this probably isn't of any help under very low
> > and very high loads, but it should provide a nice
> > improvement under medium loads...
> 
> It should provide an improvement under high VFS load (lots of
> files lookedup and not kept referenced all the time).

Not really. Under very high VFS loads we'd just scan
through the list twice and free the entries anyway.

The only time when this scanning is an improvement is
when we have something like a "working set" for the
dentry cache *and* the refill/scan rate is constant
enough that that "working set" doesn't get flooded out
by the new dentry pages.

Note that creating a new dentry doesn't set the
referenced bit exactly to avoid this from happening.

regards,

Rik
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