[PATCH] Improve comments in elision-(try)lock.c

[Dominik Vogt <vogt at linux dot vnet dot ibm dot com>]

The attached patch somwhat improved documentation of the
non-elision cases of pthread_mutex_lock and pthread_mutex_trylock.

Ciao

Dominik ^_^  ^_^

-- 

Dominik Vogt
IBM Germany

>From f8a0d78c2db32189e31f505e274809d6807cdae0 Mon Sep 17 00:00:00 2001
From: Dominik Vogt <vogt@de.ibm.com>
Date: Wed, 18 Sep 2013 06:09:36 +0000
Subject: [PATCH 1/7] x86: Improve comments in elision-(try)lock.c

---
 nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c    | 3 ++-
 nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c
index 9d00983..7854057 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c
+++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c
@@ -86,7 +86,8 @@ __lll_lock_elision (int *futex, short *adapt_count, EXTRAARG int private)
   else
     {
       /* Use a normal lock until the threshold counter runs out.
-	 Lost updates possible.  */
+	 Lost updates possible.  Due to races this might lead
+	 to *adapt_count becoming less than zero.  */
       (*adapt_count)--;
     }
 
diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c
index f6c47ef..1b6c91e 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c
+++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c
@@ -63,7 +63,8 @@ __lll_trylock_elision (int *futex, short *adapt_count)
     }
   else
     {
-      /* Lost updates are possible, but harmless.  */
+      /* Lost updates possible, but harmless.  Due to races this
+	 might lead to *adapt_count becoming less than zero.  */
       (*adapt_count)--;
     }
 
-- 
1.7.11.4

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