Finding a profiler that works, damnit
Finding a profiler that works, damnit
Posted Mar 26, 2010 21:44 UTC (Fri) by foom (subscriber, #14868)In reply to: Finding a profiler that works, damnit by sandmann
Parent article: KVM, QEMU, and kernel project management
Why does it need to happen at NMI time? Why can't you just do it in the user process's context,
before resuming execution of their code?
The setitimer(ITIMER_PROF) solution that userspace profilers use clearly works out fine for
userspace profiling. Can't you do something similar for userspace profiling from within the kernel?
The stack trace of the userspace half clearly can't change between when you received the NMI and
when you resume execution of the process...
That just leaves the complication of implementing the DWARF unwinder in the kernel, but there's
already much more complex code in the kernel...that really seems like it should be a non-issue.
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