[tip:locking/core] locking/x86: Drop a comment left over from X86_OOSTORE

From: tip-bot for Michael S. Tsirkin
Date: Fri Jan 29 2016 - 06:33:53 EST


Commit-ID: e37cee133c72c9529f74a20d9b7eb3b6dfb928b5
Gitweb: http://git.kernel.org/tip/e37cee133c72c9529f74a20d9b7eb3b6dfb928b5
Author: Michael S. Tsirkin <mst@xxxxxxxxxx>
AuthorDate: Thu, 28 Jan 2016 19:02:37 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: virtualization <virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1453921746-16178-3-git-send-email-mst@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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", \