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From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
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Subject: [Xen-devel] [PATCH 4/4] x86/mm: drop redundant smp_wmb() from
 _put_final_page_type()
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Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
 Andrew Cooper <andrew.cooper3@citrix.com>, Wei Liu <wl@xen.org>,
	=?utf-8?q?Roger_Pau_Monn=C3=A9?= <roger.pau@citrix.com>
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get_page_light()'s use of cmpxchg() is a full barrier already anyway.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2746,7 +2746,7 @@ static int _put_final_page_type(struct p
     else
     {
         BUG_ON(rc != -ERESTART);
-        smp_wmb();
+        /* get_page_light() includes a full barrier. */
         get_page_light(page);
         page->u.inuse.type_info |= PGT_partial;
     }