Messages in this thread |  | | | Date | Fri, 10 Sep 2010 02:59:27 +0200 | | From | Artur Skawina <> | | Subject | Re: [BISECTED] 2.6.35.*: horrible (exponential? >linear) slowdown to unusability (HPET) |
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On 09/10/10 00:34, Nix wrote: > It did: I found a system on which the fault was consistently > reproducible. Bisected. > > The horrible slowdowns some people are experiencing in 2.6.35 are *not* > a result of bootmem interfering with the scheduler. They are a result of > an HPET patch, specifically, this one: > > commit 30a564be9d9554c168a654eddc2165869cc0d7bf > Author: Thomas Gleixner <tglx@linutronix.de> > Date: Tue Apr 13 15:31:36 2010 +0200 > > x86, hpet: Restrict read back to affected ATI chipsets
> On (at least) my ICH10 motherboard (a Tyan S7010), running this commit > (or later) without hpet=verbose leads to one of two behaviours depending > on whether or not CONFIG_NO_HZ is on. (This system is using HPET timers > rather than the TSC even though it is a constant_tsc system, because it > is an always-on headless server and I wanted it to spend as much time in > C3 as possible. Why, yes, bisecting a bug on an always-on headless > server with a dozen client systems *was* a complete pig, why do you > ask?)
I'm seeing this too, except here it happens every couple of days of uptime, lasts for a few minutes, and then goes away. Which made bisecting a bit impractical... Thank you for doing it. HW is similar; x64 and X58/82801JI/ICH10, tsc clocksrc. Did that printk trigger? Empirically confirming that this is the problem could take weeks here, as it happens so rarely...
artur
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