Messages in this thread | | | Date | Mon, 6 Sep 2010 07:32:55 +0200 | From | Damien Wyart <> | Subject | Re: 2.6.35.*: horrible (exponential? >linear) slowdown to unusability (ACPI idle?) |
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Hello,
* Nix <nix@esperi.org.uk> [2010-09-05 01:51]: > This is a preliminary report: I haven't bisected this problem yet, or > isolated it in any significant fashion.
> What I can say is this.
> In 2.6.35.3, but not in 2.6.34.1, some of my systems experience an > increasingly severe series of stalls whenever the system is idle. The > stalls get worse at a rate above linear: about fifty seconds after they > start, I am waiting five to ten seconds for responses to keystrokes. It > is very hard to get anything much done in this situation: even > restarting is hard. 'perf top' shows nothing using the time, but the > load average is pegged at 1.
> I can verify that this does not happen on my embedded Geode box, a > 32-bit system without ACPI support. It does happen on my x86-64 systems, > all of which are running 64-bit kernels with ACPI. These systems are all > running with CONFIG_NOHZ, so I tried turning it off. The problem got > enormously worse: the kernel lasted 6.4 seconds after initial boot and > about two seconds after entering userspace before stalling completely.
I think this is related to what has been discussed in this thread: http://lkml.org/lkml/2010/7/14/11
I've not seen the problem with 2.6.35.4 yet, and only once with 2.6.35.3. Zeno said it disappeared for him when he started to use 2.6.35-stable.
So if you can reproduce it quite easily, I guess bisection (even painful) will be the best way to get (hopefuly) an idea of where the problem might come from...
-- Damien Wyart
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