2013/9/3 Christoph Lameter <cl@xxxxxxxxx>: > On Thu, 29 Aug 2013, Steven Rostedt wrote: > >> How many places use the this_cpu_*() without preemption disabled? I >> wouldn't think there's many. I never complained about another variant, >> so you need to ask those that have. The tough question for me is what >> that variant name should be ;-) > > Tried to add preemption checks but the basic issue is that many of the > checks themselves use this_cpu_ops. percpu.h is very basic to the > operation of fundamental primitives for preempt etc. Use of a BUG_ON needs > a seris of includes in percpu.h that cause more trouble. > > If I switch __this_cpu ops to check for preemption then the logic for > preemption etc must use the raw_this_cpu ops. IIUC the issue is that preempt debug checks themselves use per cpu operations that can result in preempt debug checks? Hence a recursion. Do you have an example of that? Also in this case this must be fixed anyway given the checks that already exist in smp_processor_id(), __get_cpu_var(), ... -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
