On Wed, 2007-12-12 at 16:40 +1100, Nick Piggin wrote: > On Wednesday 12 December 2007 16:11, Dave Kleikamp wrote: > > On Wed, 2007-12-12 at 15:57 +1100, Nick Piggin wrote:
> > > Anyway, I am hoping that someone will one day and test if this and > > > find it helps their workload, but on the other hand, if it doesn't > > > help anyone then we don't have to worry about adding it to the > > > kernel ;) I don't have any real setups that hammers DIO with threads. > > > I'm guessing DB2 and/or Oracle does? > > > > I'll try to get someone to run a DB2 benchmark and see what it looks > > like. > > That would be great if you could. We weren't able to get in any runs before the holidays, but we finally have some good news from our performance team: "To test the effects of the patch, an OLTP workload was run on an IBM x3850 M2 server with 2 processors (quad-core Intel Xeon processors at 2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing runs with and without the patch resulted in an overall performance benefit of ~9.8%. Correspondingly, oprofiles showed that samples from __up_read and __down_read routines that is seen during thread contention for system resources was reduced from 2.8% down to .05%. Monitoring the /proc/vmstat output from the patched run showed that the counter for fast_gup contained a very high number while the fast_gup_slow value was zero." Great work, Nick! Thanks, Shaggy -- David Kleikamp IBM Linux Technology Center -- 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/
