Re: [RFC PATCH for 4.16 02/21] rseq: Introduce restartable sequences system call (v12)

[Peter Zijlstra]

On Thu, Dec 14, 2017 at 03:14:00PM -0600, Christopher Lameter wrote:
> On Thu, 14 Dec 2017, Mathieu Desnoyers wrote:
> 
> > If we port this concept to kernel-space (as I start to understand
> > would be your wish), then a simple pointer store to the current
> > task_struct would suffice.
> 
> Certainly such a port would be beneficial for non x86 archs.
> 
> But my company has extensive user space code that maintains a lot of
> counters and does other tricks to get full performance out of the
> hardware. Such a mechanism would also be good from user space. Why keep
> the good stuff only inside the kernel?

Mathieu's proposal is for userspace, _only_ userspace.