* Jörn Engel <joern@xxxxxxxxx> 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 _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
