> On Thu, Dec 08, 2022 at 08:17:22PM +0000, Peter Lafreniere wrote: > > > Now after moving all NUMA logic into sched_numa_find_nth_cpu(), > > > else-branch of cpumask_local_spread() is just a function call, and > > > we can simplify logic by using ternary operator. > > > > > > While here, replace BUG() with WARN(). > > Why make this change? It's still as bad to hit the WARN_ON as it was before. > > For example, because of this: > > > Greg, please don't do this > > > > > ChangeSet@1.614, 2002-09-05 08:33:20-07:00, greg@xxxxxxxxx > > > USB: storage driver: replace show_trace() with BUG() > > > > that BUG() thing is _way_ out of line, and has killed a few of my machines > > several times for no good reason. It actively hurts debuggability, because > > the machine is totally dead after it, and the whole and ONLY point of > > BUG() messages is to help debugging and make it clear that we can't handle > > something. > > > > In this case, we _can_ handle it, and we're much better off with a machine > > that works and that you can look up the messages with than killing it. > > > > Rule of thumb: BUG() is only good for something that never happens and > > that we really have no other option for (ie state is so corrupt that > > continuing is deadly). > > > > Linus Fair enough. It's not like it'll be hit anyway. My concern was for if any of the 23 callers get an invalid result. I guess that if that causes a crash, then so be it. We have the warning to track down the cause. Thanks for the explanation, Peter Lafreniere <peter@xxxxxxxx>
