On 5/24/19 3:00 PM, Linus Torvalds wrote: > On Fri, May 24, 2019 at 11:54 AM Waiman Long <[email protected]> wrote: >> v2: Simplify the condition to just preempt or !preempt. >> v3: Document the imprecise nature of the percpu count. > My point was that if they are imprecise., then you shouldn't use > CONFIG_PREEMPT. > > Because CONFIG_PREEMPT doesn't matter, and the count is imprecise with > it or without it. > > So if they are imprecise, then what matters isn't whether the > operation is atomic or not, and the real issue is avout whether it > causes that "BUG: using __this_cpu_add() in preemptible" message. > > IOW, you should use the config option that matters and is relevant, > namely CONFIG_DEBUG_PREEMPT.
Yes, that makes sense. I will update the patch again. Thanks, Longman
