[PATCH v2 2/3] x86: drop a comment left over from X86_OOSTORE

From	"Michael S. Tsirkin" <mst@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 2/3] x86: drop a comment left over from X86_OOSTORE
Date	2016-01-12 23:20 +0100
Message-ID	<qQfse-7eN-9@gated-at.bofh.it> (permalink)
References	<qQfsd-7eN-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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The comment about wmb being non-nop is a left over from before commit
09df7c4c8097 ("x86: Remove CONFIG_X86_OOSTORE").

It makes no sense now: if you have an SMP system with out of order
stores, making wmb not a nop will not help.

Additionally, 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@redhat.com>
---
 arch/x86/include/asm/barrier.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 7f99726..eb220b8 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -11,11 +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("lock; addl $0,0(%%esp)" ::: "memory")
 #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
 #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
-- 
MST

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[PATCH v2 2/3] x86: drop a comment left over from X86_OOSTORE "Michael S. Tsirkin" <mst@redhat.com> - 2016-01-12 23:20 +0100
  Re: [PATCH v2 2/3] x86: drop a comment left over from X86_OOSTORE One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-01-12 23:30 +0100

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