RE: Limit hash table size

[Chen, Kenneth W]

OK, here is another revision on top of what has been discussed.  It adds
4 boot time parameters so user can override default size as needed to
suite special needs.  I will sent a separate patch for
kernel-parameters.txt if everyone is OK with this one.

- Ken

-----Original Message-----
From: Andrew Morton [mailto:akpm@xxxxxxxx] 
Sent: Thursday, February 05, 2004 3:58 PM
To: Chen, Kenneth W
Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-ia64@xxxxxxxxxxxxxxx
Subject: Re: Limit hash table size

Ken, I remain unhappy with this patch.  If a big box has 500 million
dentries or inodes in cache (is possible), those hash chains will be
more
than 200 entries long on average.  It will be very slow.

We need to do something smarter.  At least, for machines which do not
have
the ia64 proliferation-of-zones problem.

Maybe we should leave the sizing of these tables as-is, and add some
hook
which allows the architecture to scale them back.

Attachment: hash4.patch
Description: hash4.patch