diff options
| author | jhb <jhb@FreeBSD.org> | 2005-01-05 21:13:27 +0000 |
|---|---|---|
| committer | jhb <jhb@FreeBSD.org> | 2005-01-05 21:13:27 +0000 |
| commit | 65d4d80800169bac83dae081a87e3d9e14719043 (patch) | |
| tree | 08a77e52d9c917cc5536ec8885e05c9cb42f5cd1 /sys/kern | |
| parent | 90af8e5e9ad80d28a3fa66629927c8b4848f0bd5 (diff) | |
| download | FreeBSD-src-65d4d80800169bac83dae081a87e3d9e14719043.zip FreeBSD-src-65d4d80800169bac83dae081a87e3d9e14719043.tar.gz | |
Rework the optimization for spinlocks on UP to be slightly less drastic and
turn it back on. Specifically, the actual changes are now less intrusive
in that the _get_spin_lock() and _rel_spin_lock() macros now have their
contents changed for UP vs SMP kernels which centralizes the changes.
Also, UP kernels do not use _mtx_lock_spin() and no longer include it. The
UP versions of the spin lock functions do not use any atomic operations,
but simple compares and stores which allow mtx_owned() to still work for
spin locks while removing the overhead of atomic operations.
Tested on: i386, alpha
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_mutex.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index af14067..ed8f7ec 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -374,11 +374,7 @@ _mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, int line) m->mtx_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->mtx_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line); -#if defined(SMP) || LOCK_DEBUG > 0 || 1 _get_spin_lock(m, curthread, opts, file, line); -#else - critical_enter(); -#endif LOCK_LOG_LOCK("LOCK", &m->mtx_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->mtx_object, opts | LOP_EXCLUSIVE, file, line); @@ -396,11 +392,7 @@ _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line) LOCK_LOG_LOCK("UNLOCK", &m->mtx_object, opts, m->mtx_recurse, file, line); mtx_assert(m, MA_OWNED); -#if defined(SMP) || LOCK_DEBUG > 0 || 1 _rel_spin_lock(m); -#else - critical_exit(); -#endif } /* @@ -573,6 +565,7 @@ _mtx_lock_sleep(struct mtx *m, struct thread *td, int opts, const char *file, return; } +#ifdef SMP /* * _mtx_lock_spin: the tougher part of acquiring an MTX_SPIN lock. * @@ -620,6 +613,7 @@ _mtx_lock_spin(struct mtx *m, struct thread *td, int opts, const char *file, return; } +#endif /* SMP */ /* * _mtx_unlock_sleep: the tougher part of releasing an MTX_DEF lock. |
