On Mon, May 3, 2021 at 12:32 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > On Sun, May 02, 2021 at 02:08:31PM -0700, Linus Torvalds wrote: > > What is relevant is what version of gcc various distributions actually > > have reasonably easily available, and how old and relevant the > > distributions are. We did decide that (just as an example) RHEL 7 was > > too old to worry about when we updated the gcc version requirement > > last time. > > > > Last year, Arnd and Kirill (maybe others were involved too) made a > > list of distros and older gcc versions. But I don't think anybody > > actually _maintains_ such a list. It would be perhaps interesting to > > have some way to check what compiler versions are being offered by > > different distros. > > fwiw, Debian 9 aka Stretch released June 2017 had gcc 6.3 > Debian 10 aka Buster released June 2019 had gcc 7.4 *and* 8.3. > Debian 8 aka Jessie had gcc-4.8.4 and gcc-4.9.2. > > So do we care about people who haven't bothered to upgrade userspace > since 2017? If so, we can't go past 4.9. I would argue that we shouldn't care about distros that are officially end-of-life. Jessie support ended last July according to the official Debian pages at https://wiki.debian.org/LTS. It's a little harder for distros that are still officially supported, like the RHEL7 case that Linus mentioned, Debian Stretch (gcc-6.3), Slackware 14.2 (gcc-5.3), or Ubuntu 18.04 (gcc-7.3). For any of these you could make the argument one way or the other: either say we care as long as the distro cares, or the users that want to build their own kernels can be reasonably expected to either upgrade their distro or install a newer compiler manually. Looking at the Debian case specifically, I see these numbers from https://popcon.debian.org/: testing/unstable: 16730 buster/stable: 113881 stretch/oldstable: 39147 jessie/oldoldstable: 19286 Assuming the numbers of users that installed popcon are proportional to the actual number of users, that's still a large chunk of people running stretch or older. Presumably, these users are actually less likely to build their own kernels. Arnd
