Messages in this thread | | | Date | Sun, 2 Dec 2007 16:47:46 +0100 | From | Ingo Molnar <> | Subject | Re: [BUG] Strange 1-second pauses during Resume-from-RAM |
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* Jörn Engel <joern@logfs.org> wrote:
> I do. Went through 10odd runs and annotated the function right below > mcount each time. Seems to work now. > > Trouble is that it doesn't solve my real problem at hand. Something > is causing significant delays when writing to logfs. Core logfs code > is not running, but may cause whatever other code is running and > burning up all the cpu time. Wasting 100ms of "qemu-time" to write a > single page happens fairly frequently. > > With the latency tracer the problem appears to have become worse. Now > the loftlockup code triggers quite frequently. Which makes a bit of > sense, as the problem is a busy CPU, rather than an idle one.
well what does the trace say, where do the delays come from? To get a quick overview you can make tracing lighter weight by doing:
echo 0 > /proc/sys/kernel/mcount_enabled echo 1 > /proc/sys/kernel/trace_syscalls
(this turns the latency tracer into a "global strace" kind of tracer)
Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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