On Sun, Mar 15, 2009 at 08:27:08AM +0800, Linus Torvalds wrote: > > > On Sat, 14 Mar 2009, Rafael J. Wysocki wrote: > > > > The following bug entry is on the current list of known regressions > > from 2.6.28. Please verify if it still should be listed and let me know > > (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12809 > > Subject : iozone regression with 2.6.29-rc6 > > Submitter : Lin Ming <ming.m.lin@xxxxxxxxx> > > Date : 2009-02-27 9:13 (16 days old) > > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1cf6e7d83bf334cc5916137862c920a97aabc018 > > References : http://marc.info/?l=linux-kernel&m=123572630504360&w=4 > > Handled-By : Wu Fengguang <fengguang.wu@xxxxxxxxx> > > I suspect that I should just raise the default dirty limits. Wu reported > that it fixed the regression, and while he picked some rather high > percentages, I think we could certainly raise the rather aggressive > default ones. > > After all, those default percentages were picked (a) with the old dirty > logic and (b) largely at random and (c) designed to be aggressive. In > particular, that (a) means that having fixed some of the dirty accounting, > maybe the real bug is now that it was always too aggressive, just hidden > by an accounting issue. I second that. 1) The _real_ dirty threshold used to be large. 2) It is a _real_ regression. It impacts real user experiences. So when introducing Nick's correct-dirty-accounting patch, we'd better increase the dirty thresholds correspondingly. > If we raised the default ratio from 5/10 to 10/20, what happens to the > iozone regression? Maybe tomorrow. Ling Ming? In general we should not cater the thresholds for one specific workload. But this is a case of _regression_, and it would be better to raise the bars above it. Thanks, Fengguang -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
