Re: Is THREAD_INFO_IN_TASK appropriate for -mm for 4.8?

From: Ingo Molnar
Date: Wed Jul 20 2016 - 03:45:10 EST

* Andy Lutomirski <luto@xxxxxxxxxx> wrote:

> Cons: It's a bit odd to merge code that can't be enabled as-is. OTOH
> x86 could plausibly enable it for 4.8 if Ingo is okay with applying
> "x86/dumpstack: Pin the target stack in save_stack_trace_tsk()" and
> "x86: Move thread_info into task_struct" during the merge window after
> the -mm patchbomb lands.

There's quite a few risky stuff piled up already so I'd prefer if we delayed these
core bits and the enablement to v4.9.

We can carry these core bits in -tip as well, can create a tip:sched/thread_info
tree for it and such. I'd prefer that because this way we have natural proximity
between patch application, testing and eventual fixes.

Then we can expose -next to all these changes as a single, bisectable group of
commits and, should anything overly catastrophic happen, remove it and regroup our

This would really be the best approach I think, since I'd like to default-enable
all this on x86 from the very beginning.