Re: [PATCH v14 1/3] /proc/pid/status: Add support for architecture specific output

[Andy Lutomirski]

On Tue, Apr 9, 2019 at 6:55 PM Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx> wrote:
>
> The architecture specific information of the running processes could
> be useful to the userland. Add support to examine process architecture
> specific information externally.
>
> Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> Cc: Linux API <linux-api@xxxxxxxxxxxxxxx>
> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>  fs/proc/array.c         | 5 +++++
>  include/linux/proc_fs.h | 2 ++
>  2 files changed, 7 insertions(+)
>
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 2edbb657f859..331592a61718 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -401,6 +401,10 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
>         seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
>  }
>
> +void __weak arch_proc_pid_status(struct seq_file *m, struct task_struct *task)
> +{
> +}

This pointlessly bloats other architectures.  Do this instead in an
appropriate header:

#ifndef arch_proc_pid_status
static inline void arch_proc_pid_status(...)
{
}
#endif

Or add /proc/PID/x86_status, which sounds better in most respects to me.