On Wed, Feb 22, 2017 at 03:09:24PM -0800, Gleb Smirnoff wrote:
> Mateusz,
>
> why do you __predict_false() the recursion scenario? I'm afraid
> that performance loss for mispredictions could outweight the
> gain due to predictions. AFAIK, mutex recursion is still a pretty
> common event in
Mateusz,
why do you __predict_false() the recursion scenario? I'm afraid
that performance loss for mispredictions could outweight the
gain due to predictions. AFAIK, mutex recursion is still a pretty
common event in the kernel.
On Mon, Feb 20, 2017 at 07:08:36PM +, Mateusz Guzik wrote:
Author: mjg
Date: Mon Feb 20 19:08:36 2017
New Revision: 313996
URL: https://svnweb.freebsd.org/changeset/base/313996
Log:
mtx: fix spin mutexes interaction with failed fcmpset
While doing so move recursion support down to the fallback routine.
Modified:
head/sys/kern/kern_mutex.c