Re: [PATCH RFC 0/1] Document how to add a new syscall

[Peter Zijlstra <peterz@infradead.org>]

On Tue, Jul 28, 2015 at 07:59:16AM -0600, Shuah Khan wrote:
> On 07/28/2015 05:41 AM, David Drysdale wrote:
> > Given that I've gotten some of the details wrong in the past (and I've
> > seen others do likewise), I thought it might be helpful to collate the
> > best practices for adding a new system call to the kernel.
> > 
> > Apologies for the wide circulation -- I've tried to include folk who've
> > recently added or proposed a system call, as they're most likely to
> > have opinions on:
> >  - whether this a useful addition to Documentation/
> >  - whether the details of the advice are correct and complete.
> > 
> > Shuah, is there anything more that should be added for the Testing
> > section in particular?
> > 
> 
> David,
> 
> Looks good. You could add a one liner on in some cases, it might be
> necessary to install headers before test compiles. Other than that,
> the information looks good.

For perf we still use the syscall() wrapper and we have hardcoded
(fallback) syscall numbers in there in case they've not yet reached
unistd.h.

People update their kernels far more often than their userspace headers.