Re: possible bug with RAID

[Steve Lord <lord@sgi.com>]

On Tue, 2001-12-11 at 13:34, Steve Lord wrote:
> On Tue, 2001-12-11 at 12:54, Roy Sigurd Karlsbakk wrote:
> > > it would be interesting to write a simple benchmark
> > > that simply reads a file at a fixed rate.  *that* would
> > > actually simulate your app.
> > 
> > sure. I'm using tux+wget for that. I were just playing around with dd
> > 
> > > sounds like a VM/balance problem.  you didn't mention which kernel
> > > you're using.
> > 
> > 2.4.16 w/tux + xfs. The fs used on the raid vol is xfs
> 
> We just got to the bottom of a problem in xfs which was causing memory
> not to get cleaned as efficiently as it should be - it lead to dbench
> lockups on low memory systems. It is possible you are seeing a similar
> effect - we dirty all the memory and then struggle to clean it up.
> 
> Try the attached patch.
> 
> Steve
> 

OK, don't try that patch too hard, I have a better one without a race
condition on the buffer head.... it should show up in the xfs cvs tree
later today, I am going to stress this one a little harder first!

Steve