Messages in this thread | | | Date | Mon, 18 Dec 2023 13:12:46 -0500 | Subject | Re: [PATCH 19/50] locking/mutex: split out mutex_types.h | From | Waiman Long <> |
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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@linux.dev> > Cc: Peter Zijlstra<peterz@infradead.org> > Cc: Ingo Molnar<mingo@redhat.com> > Cc: Will Deacon<will@kernel.org> > Cc: Waiman Long<longman@redhat.com> > Cc: Boqun Feng<boqun.feng@gmail.com> > Signed-off-by: Kent Overstreet<kent.overstreet@linux.dev> > --- > 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
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