Messages in this thread |  | | Date | Mon, 16 Jun 2008 08:30:03 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [PATCH 3/3] relay: Add buffer-only channels; useful for early logging. |
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* Eduard - Gabriel Munteanu (eduard.munteanu@linux360.ro) wrote: > On Fri, 13 Jun 2008 10:04:57 +0300 > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > > Why do we need to change for_each_online_cpu to for_each_present_cpu? > > I guess it's because we don't have all the CPUs online at early > > boot? > > Yes, that's true. Only one CPU is online at that early point. > > > Wouldn't it then be better to implement CPU hotplug support > > instead? > > It's difficult for me to write such code, as I'm unable to test CPU > hotplug; my machines are a Turion X2 laptop and a Athlon Barton desktop > computer. So I can't turn off, or unplug in a software sense, one CPU core. > Correct me if I'm wrong, but I don't see any way to do that in /sys/devices/system/cpu/ >
See Documentation/cpu-hotplug.txt
If you need to "emulate" having many CPUs, Xen is always an option.
> But I suppose I could write a patch very carefully, and then submit to > someone that can test this. Anyway, I'll look into this and try to > understand the code without being able to test. >
Hrm, sounds like a bad idea... please try getting a test setup working, it will save you a gazillion iterations and let you stress-test your code.
Mathieu
> > Eduard >
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