Re: [RFC] block layer support for DMA IOMMU bypass mode II

[Grant Grundler <grundler@parisc-linux.org>]

On Mon, Jul 28, 2003 at 01:15:13PM +0200, Andi Kleen wrote:
> Run it with 100-500 users (reaim -f workfile... -s 100 -e 500 -i 100) 

jejb was wondering if 4k pages would cause different behaviors becuase
of file system vs page size (4k vs 16k).  ia64 uses 16k by default.
I've rebuilt the kernel with 4k page size and VMERGE != 0.
The substantially worse performance feels like a rat hole because
of 4x pressure on CPU TLB.

Ideally, we need a workload to test BIO code without a file system.
Any suggestions?

grant


iota:/mnt# reaim -f /mnt/usr/local/share/reaim/workfile.new_dbase -s100 -e 500 -i 100
REAIM Workload                                                                  
Times are in seconds - Child times from tms.cstime and tms.cutime               

Num     Parent   Child   Child  Jobs per   Jobs/min/  Std_dev  Std_dev  JTI     
Forked  Time     SysTime UTime   Minute     Child      Time     Percent         
100     118.90   21.17   214.03  5197.78    51.98      4.52     3.98     96     
200     236.75   42.54   429.94  5220.63    26.10      9.43     4.16     95     
300     354.94   64.47   644.80  5223.34    17.41      14.47    4.27     95     
400     474.50   87.01   861.09  5209.66    13.02      24.76    5.59     94     
500     594.26   109.80  1077.00 5199.78    10.40      25.36    4.49     95     
Max Jobs per Minute 5223.34                                                     
iota:/mnt#