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Date: Tue, 31 Aug 2004 01:44:58 -0700
From: William Lee Irwin III <wli@holomorphy.com>
To: Eric Valette <eric.valette@free.fr>, Andrew Morton <akpm@osdl.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: wait_on_bit_lock() must test_and_set_bit(), not test_bit()
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On Tue, Aug 31, 2004 at 01:09:16AM -0700, William Lee Irwin III wrote:
>> I very distinctly recall compiling and booting these...

On Tue, Aug 31, 2004 at 01:14:56AM -0700, William Lee Irwin III wrote:
> Index: mm2-2.6.9-rc1/kernel/wait.c

Incremental atop the fastcall fix:

wait_on_bit_lock() needs to test_and_set_bit() in the fastpath, not
test_bit().


-- wli

Index: mm2-2.6.9-rc1/include/linux/wait.h
===================================================================
--- mm2-2.6.9-rc1.orig/include/linux/wait.h	2004-08-31 01:37:55.507900064 -0700
+++ mm2-2.6.9-rc1/include/linux/wait.h	2004-08-31 01:38:34.670946376 -0700
@@ -388,7 +388,7 @@
 	DEFINE_WAIT_BIT(q, word, bit);
 	wait_queue_head_t *wqh;
 
-	if (!test_bit(bit, word))
+	if (!test_and_set_bit(bit, word))
 		return 0;
 
 	wqh = bit_waitqueue(word, bit);