From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Sun, 1 Oct 2006 06:27:44 +0000 (-0700)
Subject: [PATCH] Directed yield: direct yield of spinlocks for powerpc
X-Git-Tag: v2.6.19-rc1~598
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cdc39363d33506b0e067d41fc91f89d186bdf7f7;p=linux-2.6

[PATCH] Directed yield: direct yield of spinlocks for powerpc

Powerpc already has a directed yield for CONFIG_PREEMPT="n".  To make it
work with CONFIG_PREEMPT="y" as well the _raw_{spin,read,write}_relax
primitives need to be defined to call __spin_yield() for spinlocks and
__rw_yield() for rw-locks.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/include/asm-powerpc/spinlock.h b/include/asm-powerpc/spinlock.h
index eaccac8327..cc4cfceac6 100644
--- a/include/asm-powerpc/spinlock.h
+++ b/include/asm-powerpc/spinlock.h
@@ -285,9 +285,9 @@ static __inline__ void __raw_write_unlock(raw_rwlock_t *rw)
 	rw->lock = 0;
 }
 
-#define _raw_spin_relax(lock)	cpu_relax()
-#define _raw_read_relax(lock)	cpu_relax()
-#define _raw_write_relax(lock)	cpu_relax()
+#define _raw_spin_relax(lock)	__spin_yield(lock)
+#define _raw_read_relax(lock)	__rw_yield(lock)
+#define _raw_write_relax(lock)	__rw_yield(lock)
 
 #endif /* __KERNEL__ */
 #endif /* __ASM_SPINLOCK_H */