Re: [PATCH] Speedup SMP kernel on UP box

From: Paul Menage (pmenage@ensim.com)
Date: Sat Mar 16 2002 - 18:37:26 EST


In article <0C01A29FBAE24448A792F5C68F5EA47D238DE0@nasdaq.ms.ensim.com>,
you write:
>@@ -9,9 +9,15 @@
> */
>
> #ifdef CONFIG_SMP
>-#define LOCK "lock ; "
>+#define LOCK "\n1:\tlock ; "
>+#define LOCK_ADDR "\n" \
>+ ".section .lock.init,\"a\"\n\t" \
>+ ".align 4\n\t" \
>+ ".long 1b\n" \
>+ ".previous\n"

Why not do:

#define LOCK "1: lock ; \n" \
                 ".section .lock.init,\"a\"\n" \
                ".align 4\n"\
                ".long 1b\n"\
                ".previous\n"

Then you don't need the LOCK_ADDR macro, so most of atomic.h can be
left as is. The assembler doesn't seem to care that there's a section
change between the lock prefix and the instruction that it's locking.

Paul
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