Re: [patch 2/3] mutex subsystem: fastpath inlining

[Ingo Molnar <mingo@elte.hu>]

* Nicolas Pitre <nico@cam.org> wrote:

> > * Nicolas Pitre <nico@cam.org> wrote:
> > 
> > > Some architectures, notably ARM for instance, might benefit from 
> > > inlining the mutex fast paths. [...]
> > 
> > what is the effect on text size? Could you post the before- and 
> > after-patch vmlinux 'size kernel/test.o' output in the nondebug case, 
> > with Arjan's latest 'convert a couple of semaphore users to mutexes' 
> > patch applied? [make sure you've got enough of those users compiled in, 
> > so that the inlining cost is truly measured. Perhaps also do 
> > before/after 'size' output of a few affected .o files, without mixing 
> > kernel/mutex.o into it, like vmlinux does.]
> 
> Theory should be convincing enough. [...]

please provide actual measurements (just a simple pre-patch and 
post-patch 'size' output of vmlinux is enough), so that we can see the 
inlining cost. Note that x86 went to a non-inlined fastpath _despite_ 
having a compact CISC semaphore fastpath.

	Ingo