Re: [tip:locking/core] x86, locking/rwlocks: Enable qrwlocks on x86

From: Peter Zijlstra
Date: Wed Jun 11 2014 - 05:05:43 EST


On Wed, Jun 11, 2014 at 10:59:21AM +0200, Peter Zijlstra wrote:
> On Wed, Jun 11, 2014 at 10:14:11AM +0200, Paul Bolle wrote:
> > On Fri, 2014-06-06 at 05:20 -0700, tip-bot for Waiman Long wrote:
> > > +#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
> >
> > X86_OOSTORE was removed in v3.14, see commit 09df7c4c8097 ("x86: Remove
> > CONFIG_X86_OOSTORE"). So the first test can be removed here, as it will
> > always be true. Should I submit the trivial, but probably untested,
> > patch to do that or do you prefer to do that yourself?
>
> I was completely unaware of that removal. Yeah, I'll queue patch
> removing this new instance of it.
>
> Good to have it gone though, one little crazy less.

I've queued the below. Thanks!

---
Subject: x86, locking: No more OOSTORE nonsense
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed Jun 11 11:01:45 CEST 2014

Paul reported that X86_OOSTORE is dead, yay! Update a comment and
remove a newly added reference.

Reported-by: Paul Bolle <pebolle@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-6w40duqjdmo3sslxtvisuh7w@xxxxxxxxxxxxxx
---
arch/x86/include/asm/barrier.h | 2 +-
arch/x86/include/asm/qrwlock.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -99,7 +99,7 @@
#if defined(CONFIG_X86_PPRO_FENCE)

/*
- * For either of these options x86 doesn't have a strong TSO memory
+ * For this option x86 doesn't have a strong TSO memory
* model and we should fall back to full barriers.
*/

--- a/arch/x86/include/asm/qrwlock.h
+++ b/arch/x86/include/asm/qrwlock.h
@@ -3,7 +3,7 @@

#include <asm-generic/qrwlock_types.h>

-#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
+#ifndef CONFIG_X86_PPRO_FENCE
#define queue_write_unlock queue_write_unlock
static inline void queue_write_unlock(struct qrwlock *lock)
{


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