On Mon, Mar 15, 2021 at 03:58:07PM -0700, Nick Desaulniers wrote:
On Mon, Mar 15, 2021 at 10:53 AM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
You haven't explained why all this effort is justified to begin with.
Who cares about being able to build 4.19 or 5.4 mainline with Clang 12
and IAS?
Ah, sorry, ChromeOS and Android very much do so. (Google's production
kernels as well, though I don't think they have any 32b ARM machines).
Android is already building 4.19+ with LLVM_IAS=1 for
ARCH=arm64,x86_64,i686. ChromeOS is doing so for 5.4+ for
ARCH=arm64,x86_64 as well. I'm not sure precisely what's going on in
prodkernel land, but I know they have LLVM_IAS=1 enabled for x86_64.
So when Greg says this is "for no real users" I disagree. Maybe no
one is using LLVM_IAS=1 for ARCH=arm at this moment, but that was the
point of the backports, to enable more distros to do so.
You can't both stay on a "stable" kernel because it's "stable", but
then expect a flow of new features. The users which you've mentioned
should be migrating to newer kernels instead of attempting to backport
features they care about to stable kernels.
--
Thanks,
Sasha
