On Sat, Feb 20, 2010 at 2:01 AM, Joel Fernandes <agnel.joel@xxxxxxxxx> wrote: >> In fact the "kernel" is not interrupt-able in linux as I recall. Thus >> a misbehaving driver that enters an infinite loop will hang the whole >> machine. > ... >> Another way to ask your question is "Why isn't the linux kernel itself >> timesliced?" > > AFAIK, What you're talking about is a kernel compiled with "voluntary" > preemption.. Isn't it true that in non-voluntary preemption > (CONFIG_PREEMPT=y), the kernel execution itself can be > preempted/interrupted when it is not in a spin lock guarded critical > region? > > And since we're talking about sleeping, we're not in a critical region > anyway (we're not supposed sleep in these AFAIK) > > Let me know your thoughts & Thanks, > -Joel Joel, I think your right, but I also think (or at least suspect) that most distros are currently not setting CONFIG_PREEMPT=y. I'm running OpenSuse 11.2 with the 2.6.31 kernel currently: > zcat /proc/config.gz | grep CONFIG_PREE # CONFIG_PREEMPT_RCU is not set # CONFIG_PREEMPT_RCU_TRACE is not set CONFIG_PREEMPT_NOTIFIERS=y CONFIG_PREEMPT_NONE=y # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT is not set So I should have remembered about CONFIG_PREEMPT but my explanation was right for at least some distro kernels. Greg -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
