Lee Thanks for your help. In testing different kernels we found that using an unpatched kernel from kernel.org seems to fix the problem. I'm assuming that a patch added in the gentoo-sources patch set was creating the problem. Our once 8 minute untar is now down to 7-8 seconds with a vanilla 2.6.18.6 kernel.
If anyone is interested in our oprofile code or other info, just ask and I'll post it. Otherwise I'll be reporting this to the gentoo developers. -E > ----- Original Message ----- > From: "Elliott Johnson" <[EMAIL PROTECTED]> > To: linux-kernel@vger.kernel.org > Subject: Re: strange high system cpu usage. > Date: Fri, 30 Mar 2007 11:54:57 +0800 > > > > What problem are you trying to solve? IOW, how do you know it's not > > just an artifact of diferent load average calculation between 2.4 and > > 2.6? > > > > Are you actually seeing reduced throughput/performance? Or are you > > just looking at load average? > > > > Lee > > Well the problem is apparent, we are having abnormally high cpu > usage. It's about a > 20-40% performance hit. > > The load calculations were not between 2.4 and 2.6 kernel versions, > but between 2.6.8 and > 2.6.19. Sorry if this wasn't very clear from my last email. > > In trying to diagnose the problem I also looked at memory stats > (vmstat) and found the > 'buffered' memory statistic way off from the comparable debian > (2.6.8) install (0-300kb > versus 500mb). > > The vmstat man page has little information on this statistic and > there seems to be varying > explanations on the web. I was hoping for a decisive explanation > (or link) and possibly > advice in toggling this value (or reasons not to). > > I'm still trying to work on this at my end. Some recent tests show > that it might be > related to the megasas driver or the large number of small files we > are using on a xfs > formated 10T array. I'll keep at it. > > Thanks for your response, > > -Elliott > > = > Search for products and services at: > http://search.mail.com > > -- > Powered by Outblaze > - > 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/ > = Search for products and services at: http://search.mail.com -- Powered by Outblaze - 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/
