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Date: Sat, 27 Feb 2016 10:35:28 -0800
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Subject: Re: [PATCH v4 1/5] getcpu_cache system call: cache CPU number of
 running thread
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>,
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On Sat, Feb 27, 2016 at 6:58 AM, Peter Zijlstra <peterz@infradead.org> 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