----- Original Message ---- > From: Mike Snitzer <[EMAIL PROTECTED]> > To: Linus Torvalds <[EMAIL PROTECTED]> > Cc: Mel Gorman <[EMAIL PROTECTED]>; Martin Knoblauch <[EMAIL PROTECTED]>; > Fengguang Wu <[EMAIL PROTECTED]>; Peter Zijlstra <[EMAIL PROTECTED]>; [EMAIL > PROTECTED]; Ingo Molnar <[EMAIL PROTECTED]>; linux-kernel@vger.kernel.org; > "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>; [EMAIL PROTECTED] > Sent: Friday, January 18, 2008 11:47:02 PM > Subject: Re: regression: 100% io-wait with 2.6.24-rcX > > > I can fire up 2.6.24-rc8 in short order to see if things are vastly > > improved (as Martin seems to indicate that he is happy with > > AACRAID on 2.6.24-rc8). Although even Martin's AACRAID > > numbers from 2.6.19.2 > > are still quite good (relative to mine). Martin can you share any tuning > > you may have done to get AACRAID to where it is for you right now? Mike,
I have always been happy with the AACRAID box compared to the CCISS system. Even with the "regression" in 2.6.24-rc1..rc5 it was more than acceptable to me. For me the differences between 2.6.19 and 2.6.24-rc8 on the AACRAID setup are: - 11% (single stream) to 25% (dual/triple stream) regression in DIO. Something I do not care much about. I just measure it for reference. + the very nice behaviour when writing to different targets (mix3), which I attribute to Peter's per-dbi stuff. And until -rc6 I was extremely pleased with the cool speedup I saw on my CCISS boxes. This would have been the next "production" kernel for me. But lets discuss this under a seperate topic. It has nothing to do with the original wait-io issue. Oh, before I forget. There has been no tuning for the AACRAID. The system is an IBM x3650 with built in AACRAID and battery backed write cache. The disks are 6x142GB/15krpm in a RAID5 setup. I see one big difference between your an my tests. I do 1MB writes to simulate the behaviour of the real applications, while yours seem to be much smaller. Cheers Martin -- 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/
