Re: [PATCH] trace_syscalls: cleanup for syscalls_metadata

[Lai Jiangshan <laijs@cn.fujitsu.com>]

Steven Rostedt wrote:
> On Wed, 2010-01-06 at 20:39 +0800, Lai Jiangshan wrote:
>> NR_syscalls is compile-time constant.
> 
> The question is, is that always true on all archs, and will that always
> be true?
> 
> Unless we can guarantee somewhere that NR_syscalls must be constant on
> all archs, we can't make this change. If it is guaranteed, then sure,
> this patch is fine.
> 

It seems that there is no spec/document guarantees it.

I searched all NR_syscalls in current kernel source code,
and I found it is a constant in header file (all archs).

trace_syscalls.c has already used it as a compile-time constant:

static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);

Thanks, Lai