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

From: Linus Torvalds
Date: Sat Feb 27 2016 - 13:35:35 EST


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.

Linus