On Jan 17, 2008 8:52 AM, Martin Knoblauch <spamtrap@xxxxxxxxxxxx> wrote: > > ----- Original Message ---- > > From: Fengguang Wu <wfg@xxxxxxxxxxxxxxxx> > > To: Martin Knoblauch <knobi@xxxxxxxxxxxx> > > Cc: Mike Snitzer <snitzer@xxxxxxxxx>; Peter Zijlstra <peterz@xxxxxxxxxxxxx>; jplatte@xxxxxxxxx; Ingo Molnar <mingo@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; "linux-ext4@xxxxxxxxxxxxxxx" <linux-ext4@xxxxxxxxxxxxxxx>; Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Sent: Wednesday, January 16, 2008 1:00:04 PM > > Subject: Re: regression: 100% io-wait with 2.6.24-rcX > > > > On Wed, Jan 16, 2008 at 01:26:41AM -0800, Martin Knoblauch wrote: > > > > For those interested in using your writeback improvements in > > > > production sooner rather than later (primarily with ext3); what > > > > recommendations do you have? Just heavily test our own 2.6.24 > > + > > > your > > > > evolving "close, but not ready for merge" -mm writeback patchset? > > > > > > > Hi Fengguang, Mike, > > > > > > I can add myself to Mikes question. It would be good to know > > a > > > "roadmap" for the writeback changes. Testing 2.6.24-rcX so far has > > been > > > showing quite nice improvement of the overall writeback situation and > > it > > > would be sad to see this [partially] gone in 2.6.24-final. > > Linus > > > apparently already has reverted "...2250b". I will definitely repeat my > > tests > > > with -rc8. and report. > > > > Thank you, Martin. Can you help test this patch on 2.6.24-rc7? > > Maybe we can push it to 2.6.24 after your testing. > > > Hi Fengguang, > > something really bad has happened between -rc3 and -rc6. Embarrassingly I did not catch that earlier :-( > > Compared to the numbers I posted in http://lkml.org/lkml/2007/10/26/208 , dd1 is now at 60 MB/sec (slight plus), while dd2/dd3 suck the same way as in pre 2.6.24. The only test that is still good is mix3, which I attribute to the per-BDI stuff. > > At the moment I am frantically trying to find when things went down. I did run -rc8 and rc8+yourpatch. No difference to what I see with -rc6. Sorry that I cannot provide any input to your patch. > > Depressed > Martin Martin, I've backported Peter's perbdi patchset to 2.6.22.x. I can share it with anyone who might be interested. As expected, it has yielded 2.6.24-rcX level scaling. Given the test result matrix you previously posted, 2.6.22.x+perbdi might give you what you're looking for (sans improved writeback that 2.6.24 was thought to be providing). That is, much improved scaling with better O_DIRECT and network throughput. Just a thought... Unfortunately, my priorities (and computing resources) have shifted and I won't be able to thoroughly test Fengguang's new writeback patch on 2.6.24-rc8... whereby missing out on providing justification/testing to others on _some_ improved writeback being included in 2.6.24 final. Not to mention the window for writeback improvement is all but closed considering the 2.6.24-rc8 announcement's 2.6.24 final release timetable. regards, Mike - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
