On Mon, 2007-11-12 at 10:45 +0100, Peter Zijlstra wrote: > On Mon, 2007-11-12 at 10:14 +0800, Zhang, Yanmin wrote: > > > > Subject: mm: speed up writeback ramp-up on clean systems > > > > I tested kernel 2.6.23, 2,6,24-rc2, 2.6.24-rc2_peter(2.6.24-rc2+this patch). > > > > 1) Compare among first/second/following running > > 2.6.23: second run of iozone will get about 28% improvement than first run. > > Following run is very stable like 2nd run. > > 2.6.24-rc2: second run of iozone will get about 170% improvement than first > > run. 3rd run > > will get about 80% improvement than 2nd. Following run is very stable > > like 3rd run. > > 2.6.24-rc2_peter: second run of iozone will get about 14% improvement than > > first run. Following > > run is mostly stable like 2nd run. > > So the new patch really improves the first run result. Comparing wiht > > 2.6.24-rc2, 2.6.24-rc2_peter > > has 330% improvement on the first run. > > > > 2) Compare among different kernels(based on the stable highest result): > > 2.6.24-rc2 has about 50% regression than 2.6.23. > > 2.6.24-rc2_peter has the same result like 2.6.24-rc2. > > > > From this point of view, above patch has no improvement. :) > > Drad, still good test results though. > > Could you describe you system in detail, that is, you have 8GB of memory > and 8 cpus (2*quad?). Yes.
> How many disks does it have 1 machine uses 1 AHCI SATA. Other machines use hardware raid0. > and are those > aggregated using md or dm? No. > What filesystem do you use? Ext3. I got the regression on my a couple of machines. Pls. try command #iozone -i 0 -r 4k -s 512m -yanmin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
