On Tue, Feb 18, 2020 at 08:34:05AM -0800, Paul E. McKenney wrote: > On Tue, Feb 18, 2020 at 12:43:34PM +0100, Peter Zijlstra wrote: > > Well, I didn't get further than the Changelog fails to describe an > > actual problem and it looks like compare-against-a-constant. > > > > (worse, it masks off everything but the 2 lowest bits, so even if there > > was a problem with load-tearing, it still wouldn't matter) > > There is still the possibility of load fusing. Agreed; that can be an issue. But if so, that then needs to be stated. > And the possibility > of defending against possible future changes as well as the current > snapshot of the code base. Sure; and like I said, if you want to use READ_ONCE() I'm not going to argue. > > I'm not going to argue with you if you want to use READ_ONCE() vs > > data_race() and a comment to denote false-positive KCSAN warnings, but I > > do feel somewhat strongly that the Changelog should describe the actual > > problem -- if there is one -- or just flat out state that this is to > > make KCSAN shut up but the code is fine. > > The problem is that "the code is fine" is highly subjective and varies > over time. :-/ > > But in this case there was a real problem, just that I got confused > when analyzing. Shit happens :-) > > That is; every KCSAN report should be analysed, right? All I'm asking is > > for that analysis to end up in the Changelog. > > Before responding further, I have to ask... > > Are you intending your "every KCSAN report should be analyzed" to apply > globally or just when someone creates a patch based on such a report? Ideally every KCSAN report, but that is a longer term effort. But specifically, when someone has written a patch, I expect that same someone to have analysed the code. Then it also makes sense to put that in the Changelog. > In any case, you have acked this patch's successor (thank you very > much!), so on this specific patch (or more accurately, its successor) > I presume that we are all good. We are. That new patch describes a clear problem and fixes it. Anyway, the reaoson I'm being difficuly is partly because on the one hand I'm just an annoying pendant at times, but also because I've seen a bunch of, let's say, hasty, KCSAN patches.
