On Wed, Feb 16, 2022 at 04:15:20PM +0100, Miroslav Benes wrote: > > > I subscribe to llvm@xxxxxxxxxxxxxxx and happen to notice this message > > > (can't keep up with the changes...) > > > I am a bit concerned with this option and replied last time on > > > https://lore.kernel.org/r/20220105032456.hs3od326sdl4zjv4@xxxxxxxxxx > > > > > > My full reasoning is on > > > https://maskray.me/blog/2020-11-15-explain-gnu-linker-options#z-unique-symbol > > > > Ah, right. Also discussed here: > > > > https://lore.kernel.org/all/20210123225928.z5hkmaw6qjs2gu5g@xxxxxxxxxx/T/#u > > https://lore.kernel.org/all/20210125172124.awabevkpvq4poqxf@treble/ > > > > I'm not qualified to comment on LTO/PGO stability issues, but it doesn't > > sound good. And we want to support livepatch for LTO kernels. > > Hm, bear with me, because I am very likely missing something which is > clear to everyone else... > > Is the stability really a problem for the live patching (and I am talking > about the live patching only here. It may be a problem elsewhere, but I am > just trying to understand.)? I understand that two different kernel builds > could have a different name mapping between the original symbols and their > unique renames. Not nice. But we can prepare two different live patches > for these two different kernels. Something one would like to avoid if > possible, but it is not impossible. Am I missing something? Maybe Fāng-ruì can clarify, but my understanding was that the stability issue affects the kernel in general (particularly if LTO or PGO is enabled) and isn't necessarily specific to livepatch itself. -- Josh
