On Wed, Sep 26, 2012 at 03:26:11PM +0200, Peter Zijlstra wrote: > On Wed, 2012-09-26 at 15:20 +0200, Andrew Jones wrote: > > Wouldn't a clean solution be to promote a task's scheduler > > class to the spinner class when we PLE (or come from some special > > syscall > > for userspace spinlocks?)? > > Userspace spinlocks are typically employed to avoid syscalls.. I'm guessing there could be a slow path - spin N times and then give up and yield. > > > That class would be higher priority than the > > fair class and would schedule in FIFO order, but it would only run its > > tasks for short periods before switching. > > Since lock hold times aren't limited, esp. for things like userspace > 'spin' locks, you've got a very good denial of service / opportunity for > abuse right there. Maybe add some throttling to avoid overuse/maliciousness? > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
