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authorPaul Murphy <murphyp@linux.vnet.ibm.com>2015-08-27 09:48:04 -0500
committerTulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>2015-10-27 17:27:41 -0200
commit72f1463df85a522bfd1568e47bd81371522ee358 (patch)
treea257dcbec150b619574c29326f89ee10d013891f /sysdeps/powerpc/nptl
parent76c5ae00284d98f1994434c570bdcde9dbc6b49e (diff)
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powerpc: Fix usage of elision transient failure adapt param
The skip_lock_out_of_tbegin_retries adaptive parameter was
not being used correctly, nor as described.  This prevents
a fallback for all users of the lock if a transient abort
occurs within the accepted number of retries.

	[BZ #19174]
	* sysdeps/powerpc/nptl/elide.h (__elide_lock): Fix usage of
	.skip_lock_out_of_tbegin_retries.
	* sysdeps/unix/sysv/linux/powerpc/elision-lock.c
	(__lll_lock_elision): Likewise, and respect a value of
	try_tbegin <= 0.
Diffstat (limited to 'sysdeps/powerpc/nptl')
-rw-r--r--sysdeps/powerpc/nptl/elide.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/sysdeps/powerpc/nptl/elide.h b/sysdeps/powerpc/nptl/elide.h
index 12171f45dc..2e1e443278 100644
--- a/sysdeps/powerpc/nptl/elide.h
+++ b/sysdeps/powerpc/nptl/elide.h
@@ -27,7 +27,7 @@
    configurations.  Returns true if the system should retry again or false
    otherwise.  */
 static inline bool
-__get_new_count (uint8_t *adapt_count)
+__get_new_count (uint8_t *adapt_count, int attempt)
 {
   /* A persistent failure indicates that a retry will probably
      result in another failure.  Use normal locking now and
@@ -40,7 +40,7 @@ __get_new_count (uint8_t *adapt_count)
     }
   /* Same logic as above, but for a number of temporary failures in a
      a row.  */
-  else if (__elision_aconf.skip_lock_out_of_tbegin_retries > 0
+  else if (attempt <= 1 && __elision_aconf.skip_lock_out_of_tbegin_retries > 0
 	   && __elision_aconf.try_tbegin > 0)
     *adapt_count = __elision_aconf.skip_lock_out_of_tbegin_retries;
   return true;
@@ -78,7 +78,7 @@ __get_new_count (uint8_t *adapt_count)
 	      __builtin_tabort (_ABORT_LOCK_BUSY);			\
 	    }								\
 	  else								\
-	    if (!__get_new_count(&adapt_count))				\
+	    if (!__get_new_count (&adapt_count,i))			\
 	      break;							\
 	}								\
     ret;								\