On Mon, 2015-08-03 at 12:51 +0100, Stefano Stabellini wrote: > On Mon, 3 Aug 2015, Ian Campbell wrote: > > From: David Vrabel <david.vra...@citrix.com> > > > > Instead of cpu_relax() while spinning and observing the ticket head, > > introduce arch_lock_relax() which executes a WFE instruction. After > > the ticket head is changed call arch_lock_signal() to execute an SEV > > instruction (with the required DSB first) to wake any spinners. > > > > This should improve power consumption when locks are contented and > > spinning. > > > > For consistency also move arch_lock_(acquire|release)_barrier to > > asm/spinlock.h. > > > > Booted the result on arm32 (Midway) and arm64 (Mustang). Build test > > only on amd64. > > > > Signed-off-by: David Vrabel <david.vra...@citrix.com> > > [ijc: add barrier, rename as arch_lock_*, move arch_lock_*_barrier, > > test] > > Signed-off-by: Ian Campbell <ian.campb...@citrix.com> > > Cc: Stefano Stabellini <stefano.stabell...@eu.citrix.com> > > Cc: Jan Beulich <jbeul...@suse.com> > > Cc: Andrew Cooper <andrew.coop...@citrix.com> > > I don't know why you are moving arch_lock_(acquire|release)_barrier to > spinlock.h as part of this patch,
It's literally explained two paragraphs above... "For consistency", i.e. to put arch_lock_* in the same place. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
