lkml.org 
[lkml]   [2001]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Ext2 Directory Index - Delete Performance
On Thu, 19 Apr 2001, Daniel Phillips wrote:
> Jan Harkes wrote:
> > On Thu, Apr 19, 2001 at 02:27:48AM +0200, Daniel Phillips wrote:
> > > more memory. If you have enough memory, the inode cache won't thrash,
> > > and even when it does, it does so gracefully - performance falls off
> > > nice and slowly. For example, 250 Meg of inode cache will handle 2
> > > million inodes with no thrashing at all.
> >
> > What inode cache are you talking about? According to the slabinfo output
> > on my machine every inode takes up 480 bytes in the inode_cache slab. So
> > 250MB is only able to hold about half a million inodes in memory.
>
> Sorry, I was a little loose with terminology there. I should have
> said "inode blocks in cache". The inode cache is related. When an
> Ext2 inode is pushed out of the inode cache it gets transfered to a
> dirty block in memory, where it shrinks to 128 bytes and shares the
> block with 31 other inodes. These blocks are in the buffer cache, and
> this is the cache I'm talking about.

Hmmm, considering this, it may be wise to limit the amount of
inodes in the inode cache to, say, 10% of RAM ... because we
can cache MORE inodes if we store them in the buffer cache
instead!

regards,

Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

http://www.surriel.com/
http://www.conectiva.com/ http://distro.conectiva.com.br/

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:26    [W:0.042 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site