[GIT PULL] percpu + mutex fixes

Ingo Molnar
2009-04-10T19:42:29Z

* Ingo Molnar <mingo@elte.hu> wrote:

> Now i understand the rush ...
>
> Yes, moving the APIs to the generic header should properly expose
> the wrapped default implementations. I'll test your patch in a
> minute.

Alpha builds fine with your patch:

LD .tmp_vmlinux2
KSYM .tmp_kallsyms2.S
AS .tmp_kallsyms2.o
LD vmlinux
SYSMAP System.map

Linus,

If that patch is OK to you too, please pull the latest
core-fixes-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core-fixes-for-linus

it includes this fix and a pending mutex fixlet.

Thanks,

Ingo

------------------>
Heiko Carstens (1):
mutex: have non-spinning mutexes on s390 by default

Tejun Heo (1):
percpu: unbreak alpha percpu

arch/Kconfig | 3 ++
arch/s390/Kconfig | 1 +
include/asm-generic/percpu.h | 52 ------------------------------------------
include/linux/percpu.h | 52 ++++++++++++++++++++++++++++++++++++++++++
kernel/mutex.c | 3 +-
5 files changed, 58 insertions(+), 53 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index dc81b34..78a35e9 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -109,3 +109,6 @@ config HAVE_CLK

config HAVE_DMA_API_DEBUG
bool
+
+config HAVE_DEFAULT_NO_SPIN_MUTEXES
+ bool
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index dcb667c..2eca5fe 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -82,6 +82,7 @@ config S390
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_SYSCALL_WRAPPERS
select HAVE_FUNCTION_TRACER
+ select HAVE_DEFAULT_NO_SPIN_MUTEXES
select HAVE_OPROFILE
select HAVE_KPROBES
select HAVE_KRETPROBES
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 00f45ff..b0e63c6 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -80,56 +80,4 @@ extern void setup_per_cpu_areas(void);
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
__typeof__(type) per_cpu_var(name)

-/*
- * Optional methods for optimized non-lvalue per-cpu variable access.
- *
- * @var can be a percpu variable or a field of it and its size should
- * equal char, int or long. percpu_read() evaluates to a lvalue and
- * all others to void.
- *
- * These operations are guaranteed to be atomic w.r.t. preemption.
- * The generic versions use plain get/put_cpu_var(). Archs are
- * encouraged to implement single-instruction alternatives which don't
- * require preemption protection.
- */
-#ifndef percpu_read
-# define percpu_read(var) \
- ({ \
- typeof(per_cpu_var(var)) __tmp_var__; \
- __tmp_var__ = get_cpu_var(var); \
- put_cpu_var(var); \
- __tmp_var__; \
- })
-#endif
-
-#define __percpu_generic_to_op(var, val, op) \
-do { \
- get_cpu_var(var) op val; \
- put_cpu_var(var); \
-} while (0)
-
-#ifndef percpu_write
-# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
-#endif
-
-#ifndef percpu_add
-# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
-#endif
-
-#ifndef percpu_sub
-# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
-#endif
-
-#ifndef percpu_and
-# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
-#endif
-
-#ifndef percpu_or
-# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
-#endif
-
-#ifndef percpu_xor
-# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
-#endif
-
#endif /* _ASM_GENERIC_PERCPU_H_ */
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index ee5615d..cfda2d5 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -168,4 +168,56 @@ static inline void free_percpu(void *p)
#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
__alignof__(type))

+/*
+ * Optional methods for optimized non-lvalue per-cpu variable access.
+ *
+ * @var can be a percpu variable or a field of it and its size should
+ * equal char, int or long. percpu_read() evaluates to a lvalue and
+ * all others to void.
+ *
+ * These operations are guaranteed to be atomic w.r.t. preemption.
+ * The generic versions use plain get/put_cpu_var(). Archs are
+ * encouraged to implement single-instruction alternatives which don't
+ * require preemption protection.
+ */
+#ifndef percpu_read
+# define percpu_read(var) \
+ ({ \
+ typeof(per_cpu_var(var)) __tmp_var__; \
+ __tmp_var__ = get_cpu_var(var); \
+ put_cpu_var(var); \
+ __tmp_var__; \
+ })
+#endif
+
+#define __percpu_generic_to_op(var, val, op) \
+do { \
+ get_cpu_var(var) op val; \
+ put_cpu_var(var); \
+} while (0)
+
+#ifndef percpu_write
+# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
+#endif
+
+#ifndef percpu_add
+# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
+#endif
+
+#ifndef percpu_sub
+# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
+#endif
+
+#ifndef percpu_and
+# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
+#endif
+
+#ifndef percpu_or
+# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
+#endif
+
+#ifndef percpu_xor
+# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
+#endif
+
#endif /* __LINUX_PERCPU_H */
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 5d79781..507cf2b 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -148,7 +148,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,

preempt_disable();
mutex_acquire(&lock->dep_map, subclass, 0, ip);
-#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES)
+#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES) && \
+ !defined(CONFIG_HAVE_DEFAULT_NO_SPIN_MUTEXES)
/*
* Optimistic spinning.
*