On 12/15/23 22:26, Kent Overstreet
wrote:
Trimming down sched.h dependencies: we don't want to include more than the base types. Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Waiman Long <longman@xxxxxxxxxx> Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> --- include/linux/mutex.h | 52 +-------------------------- include/linux/mutex_types.h | 71 +++++++++++++++++++++++++++++++++++++ include/linux/sched.h | 2 +- 3 files changed, 73 insertions(+), 52 deletions(-) create mode 100644 include/linux/mutex_types.h diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a33aa9eb9fc3..0dfba5df6524 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -20,6 +20,7 @@ #include <linux/osq_lock.h> #include <linux/debug_locks.h> #include <linux/cleanup.h> +#include <linux/mutex_types.h> #ifdef CONFIG_DEBUG_LOCK_ALLOC # define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ @@ -33,49 +34,6 @@ #ifndef CONFIG_PREEMPT_RT -/* - * Simple, straightforward mutexes with strict semantics: - * - * - only one task can hold the mutex at a time - * - only the owner can unlock the mutex - * - multiple unlocks are not permitted - * - recursive locking is not permitted - * - a mutex object must be initialized via the API - * - a mutex object must not be initialized via memset or copying - * - task may not exit with mutex held - * - memory areas where held locks reside must not be freed - * - held mutexes must not be reinitialized - * - mutexes may not be used in hardware or software interrupt - * contexts such as tasklets and timers - * - * These semantics are fully enforced when DEBUG_MUTEXES is - * enabled. Furthermore, besides enforcing the above rules, the mutex - * debugging code also implements a number of additional features - * that make lock debugging easier and faster: - * - * - uses symbolic names of mutexes, whenever they are printed in debug output - * - point-of-acquire tracking, symbolic lookup of function names - * - list of all locks held in the system, printout of them - * - owner tracking - * - detects self-recursing locks and prints out all relevant info - * - detects multi-task circular deadlocks and prints out all affected - * locks and tasks (and only those tasks) - */ -struct mutex { - atomic_long_t owner; - raw_spinlock_t wait_lock; -#ifdef CONFIG_MUTEX_SPIN_ON_OWNER - struct optimistic_spin_queue osq; /* Spinner MCS lock */ -#endif - struct list_head wait_list; -#ifdef CONFIG_DEBUG_MUTEXES - void *magic; -#endif -#ifdef CONFIG_DEBUG_LOCK_ALLOC - struct lockdep_map dep_map; -#endif -}; - #ifdef CONFIG_DEBUG_MUTEXES #define __DEBUG_MUTEX_INITIALIZER(lockname) \ @@ -131,14 +89,6 @@ extern bool mutex_is_locked(struct mutex *lock); /* * Preempt-RT variant based on rtmutexes. */ -#include <linux/rtmutex.h>
Including rtmutex.h here means that mutex_types.h is no longer a simple header for types only. So unless you also break out a rtmutex_types.h, it is inconsistent.
Besides, the kernel/sched code does use mutex_lock/unlock calls quite frequently. With this patch, mutex.h will not be directly included. I suspect that it is indirectly included via other header files. This may be an issue with some configurations.
Cheers, Longman
