On 3/17/21 1:45 PM, Peter Zijlstra wrote:
On Wed, Mar 17, 2021 at 06:40:27PM +0100, Peter Zijlstra wrote:On Wed, Mar 17, 2021 at 05:48:48PM +0100, Peter Zijlstra wrote:I think you'll find that if you use ww_mutex_init() it'll all work. Let me go and zap this patch, and then I'll try and figure out why DEFINE_WW_MUTEX() is buggered.Moo, I can't get the compiler to do as I want :/ The below is so close but doesn't actually compile.. Maybe we should just give up on DEFINE_WW_MUTEX and simply remove it. --- diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 0cd631a19727..85f50538f26a 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -129,12 +129,15 @@ do { \ # define __DEP_MAP_MUTEX_INITIALIZER(lockname) #endif-#define __MUTEX_INITIALIZER(lockname) \+#define ___MUTEX_INITIALIZER(lockname, depmap) \ { .owner = ATOMIC_LONG_INIT(0) \ , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ __DEBUG_MUTEX_INITIALIZER(lockname) \ - __DEP_MAP_MUTEX_INITIALIZER(lockname) } + depmap } + +#define __MUTEX_INITIALIZER(lockname) \ + ___MUTEX_INITIALIZER(lockname, __DEP_MAP_MUTEX_INITIALIZER(lockname))#define DEFINE_MUTEX(mutexname) \struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index 6ecf2a0220db..c62a030652b4 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -50,9 +50,17 @@ struct ww_acquire_ctx {#ifdef CONFIG_DEBUG_LOCK_ALLOC# define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) \ - , .ww_class = class + , .ww_class = &(class) + +# define __DEP_MAP_WW_MUTEX_INITIALIZER(lockname, class) \ + , .dep_map = { \ + .key = &(class).mutex_key, \ + .name = (class).mutex_name, \,name = #class "_mutex", \ and it 'works', but shees!
The name string itself may be duplicated for multiple instances of DEFINE_WW_MUTEX(). Do you want to keep DEFINE_WW_MUTEX() or just use ww_mutex_init() for all?
I notice that the problem with DEFINE_WW_MUTEX is that the ww_mutex themselves has null key instead of the same key from the ww_class as with ww_mutex_init().
Cheers, Longman
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