On Mon, Apr 16, 2018 at 12:30:19PM -0400, Steven Rostedt wrote: >On Mon, 16 Apr 2018 16:19:14 +0000 >Sasha Levin <alexander.le...@microsoft.com> wrote: > >> >Wait! What does that mean? What's the purpose of stable if it is as >> >broken as mainline? >> >> This just means that if there is a fix that went in mainline, and the >> fix is broken somehow, we'd rather take the broken fix than not. >> >> In this scenario, *something* will be broken, it's just a matter of >> what. We'd rather have the same thing broken between mainline and >> stable. > >Honestly, I think that removes all value of the stable series. I >remember when the stable series were first created. People were saying >that it wouldn't even get to more than 5 versions, because the bar for >backporting was suppose to be very high. Today it's just a fork of the >kernel at a given version. No more features, but we will be OK with >regressions. I'm struggling to see what the benefit of it is suppose to >be?
It's not "OK with regressions". Let's look at a hypothetical example: You have a 4.15.1 kernel that has a broken printf() behaviour so that when you: pr_err("%d", 5) Would print: "Microsoft Rulez" Bad, right? So you went ahead and fixed it, and now it prints "5" as you might expect. But alas, with your patch, running: pr_err("%s", "hi!") Would show a cat picture for 5 seconds. Should we take your patch in -stable or not? If we don't, we're stuck with the original issue while the mainline kernel will behave differently, but if we do - we introduce a new regression. So it's not the case that a -stable kernel will have *more* regression, it'll just have similar ones to mainline.