Hi Peter, On Fri, 2018-03-16 at 11:11 +0100, Peter Zijlstra wrote: > On Thu, Mar 15, 2018 at 09:39:31AM +0000, Alexey Brodkin wrote: > > Hi Peter, > > > > On Thu, 2018-03-15 at 09:27 +0100, Peter Zijlstra wrote: > > > On Wed, Mar 14, 2018 at 01:19:01PM -0700, Vineet Gupta wrote: > > > > +CC Peter since we have his attention ;-) > > > > > > Yeah, timezone collision there, I typically sleep at 1am ;-) > > > > > > > On 03/01/2018 07:13 AM, Alexey Brodkin wrote: > > > > > Hi Vineet, > > > > > > > > > > Just noticed that in comments for smp_call_function_many() it is said that > > > > > preemption must be disabled during its execution. And that function gets executed > > > > > among other ways like that: > > > > > -------------------------->8----------------------- > > > > > flush_tlb_range() > > > > > -> on_each_cpu_mask() > > > > > -> smp_call_function_many() > > > > > -------------------------->8----------------------- > > > > > > > > In general I prefer not to - Peter what say you ? > > > > > > The comment with smp_call_function_many() is correct, it relies on > > > preemption being disabled in a number of ways. I would expect > > > this_cpu_ptr() for example to complain when used with preemption > > > enabled (CONFIG_DEBUG_PREEMPT). > > So on_each_cpu_mask() already disables preemption around calling > smp_call_function_many(). Right that happens in get_cpu() so then we're golden here. Thanks for pointing out - was not clear immediately from the code :) -Alexey
