Re: [PATCH v4 1/5] getcpu_cache system call: cache CPU number of running thread

[Peter Zijlstra]

On Sat, Feb 27, 2016 at 10:35:28AM -0800, Linus Torvalds wrote:
> On Sat, Feb 27, 2016 at 6:58 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > Paul's patches have the following structure:
> >
> > struct thread_local_abi {
> >         union {
> >                 struct {
> >                         u32     cpu_id;
> >                         u32     seq;
> >                 };
> >                 u64 cpu_seq;
> >         };
> >         unsigned long post_commit_ip;
> > };
> 
> Please don't do "unsigned long" in ABI structures any more.
> 
> Make it u64, and make sure it is 64-bit aligned (which it would be in
> this case). Make it so that we don't have to have separate compat
> paths.

Yes, for sure. I was 'only' trying to reflect the state of the last rseq
patches. But yes, I should have called that out and avoided 'confusion'.