linux-kernel - [tip:locking/core] locking/x86: Drop a comment left over from X86

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Date:	Fri, 29 Jan 2016 03:32:30 -0800
From:	"tip-bot for Michael S. Tsirkin" <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	luto@...nel.org, tglx@...utronix.de,
	virtualization@...ts.linux-foundation.org, luto@...capital.net,
	dbueso@...e.de, peterz@...radead.org, linux-kernel@...r.kernel.org,
	mingo@...nel.org, paulmck@...ux.vnet.ibm.com, mst@...hat.com,
	dvlasenk@...hat.com, bp@...e.de, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, andreyknvl@...gle.com,
	dave@...olabs.net, brgerst@...il.com, bp@...en8.de, hpa@...or.com
Subject: [tip:locking/core] locking/x86:
  Drop a comment left over from X86_OOSTORE

Commit-ID:  e37cee133c72c9529f74a20d9b7eb3b6dfb928b5
Gitweb:     http://git.kernel.org/tip/e37cee133c72c9529f74a20d9b7eb3b6dfb928b5
Author:     Michael S. Tsirkin <mst@...hat.com>
AuthorDate: Thu, 28 Jan 2016 19:02:37 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 29 Jan 2016 09:40:10 +0100

locking/x86: Drop a comment left over from X86_OOSTORE

The comment about wmb being non-NOP to deal with non-Intel CPUs
is a left over from before the following commit:

  09df7c4c8097 ("x86: Remove CONFIG_X86_OOSTORE")

It makes no sense now: in particular, wmb() is not a NOP even for
regular Intel CPUs because of weird use-cases e.g. dealing with
WC memory.

Drop this comment.

Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@...gle.com>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Borislav Petkov <bp@...e.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Davidlohr Bueso <dave@...olabs.net>
Cc: Davidlohr Bueso <dbueso@...e.de>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: virtualization <virtualization@...ts.linux-foundation.org>
Link: http://lkml.kernel.org/r/1453921746-16178-3-git-send-email-mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/include/asm/barrier.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index a65bdb1..a291745 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -11,10 +11,6 @@
  */
 
 #ifdef CONFIG_X86_32
-/*
- * Some non-Intel clones support out of order store. wmb() ceases to be a
- * nop for these.
- */
 #define mb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "mfence", \
 				      X86_FEATURE_XMM2) ::: "memory", "cc")
 #define rmb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "lfence", \