RE: Kernel performance in reference to 2.4.5pre1

[DICKENS,CARY]

I'll put this on my priority list to look into.  When I get the numbers,
I'll squeak again.

Thanks, 
Cary

> -----Original Message-----
> From: Andrew Morton [mailto:[e-mail]]
> Sent: Thursday, October 18, 2001 12:34 PM
> To: DICKENS,CARY (HP-Loveland,ex2)
> Cc: Kernel Mailing List (E-mail); HABBINGA,ERIK (HP-Loveland,ex1)
> Subject: Re: Kernel performance in reference to 2.4.5pre1
> 
> 
> "DICKENS,CARY (HP-Loveland,ex2)" wrote:
> > 
> > 2.4.5pre1 is the base for comparison,
> > 
> > [ figures showing that more recent kernels suck ]
> > 
> 
> SFS is a rather specialised workload, and synchronous NFS exports
> are not a thing which gets a lot of attention.  It could be one
> small, hitherto unnoticed change which caused this performance
> regression.  And it appears that the change occurred between 2.4.5
> and 2.4.7.
> 
> We don't know whether this slowdown is caused by changes in the VM,
> the filesystem, the block device layer, nfsd or networking. 
> For example,
> ksoftirqd was introduced between 2.4.5 and 2.4.7.  Could it be that?
> 
> For all these reasons it would be really helpful if you could
> go back and test the 2.4.6-preX and 2.4.7-preX kernels (binary search)
> and tell us if there was a particular release which caused 
> this decrease in
> throughput.
> 
> If it can be pinned down to a particular patch then there's a good
> chance that it can be fixed.
>