diff options
Diffstat (limited to 'kern/rtmutex.c')
| -rw-r--r-- | kern/rtmutex.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/kern/rtmutex.c b/kern/rtmutex.c index 0070b93f..9fcc4e0e 100644 --- a/kern/rtmutex.c +++ b/kern/rtmutex.c @@ -21,12 +21,64 @@ #include <stdint.h> #include <kern/atomic.h> +#include <kern/init.h> +#include <kern/macros.h> #include <kern/rtmutex.h> #include <kern/rtmutex_i.h> #include <kern/rtmutex_types.h> #include <kern/thread.h> #include <kern/turnstile.h> +/* Set to 1 to enable debugging */ +#define RTMUTEX_DEBUG 0 + +#if RTMUTEX_DEBUG + +enum { + RTMUTEX_SC_WAIT_SUCCESSES, + RTMUTEX_SC_WAIT_ERRORS, + RTMUTEX_SC_DOWNGRADES, + RTMUTEX_SC_ERROR_DOWNGRADES, + RTMUTEX_SC_CANCELED_DOWNGRADES, + RTMUTEX_NR_SCS +}; + +static struct syscnt rtmutex_sc_array[RTMUTEX_NR_SCS]; + +static void +rtmutex_register_sc(unsigned int index, const char *name) +{ + assert(index < ARRAY_SIZE(rtmutex_sc_array)); + syscnt_register(&rtmutex_sc_array[index], name); +} + +static void +rtmutex_setup_debug(void) +{ + rtmutex_register_sc(RTMUTEX_SC_WAIT_SUCCESSES, + "rtmutex_wait_successes"); + rtmutex_register_sc(RTMUTEX_SC_WAIT_ERRORS, + "rtmutex_wait_errors"); + rtmutex_register_sc(RTMUTEX_SC_DOWNGRADES, + "rtmutex_downgrades"); + rtmutex_register_sc(RTMUTEX_SC_ERROR_DOWNGRADES, + "rtmutex_error_downgrades"); + rtmutex_register_sc(RTMUTEX_SC_CANCELED_DOWNGRADES, + "rtmutex_canceled_downgrades"); +} + +static void +rtmutex_inc_sc(unsigned int index) +{ + assert(index < ARRAY_SIZE(rtmutex_sc_array)); + syscnt_inc(&rtmutex_sc_array[index]); +} + +#else /* RTMUTEX_DEBUG */ +#define rtmutex_setup_debug() +#define rtmutex_inc_sc(x) +#endif /* RTMUTEX_DEBUG */ + static struct thread * rtmutex_get_thread(uintptr_t owner) { @@ -81,6 +133,8 @@ rtmutex_lock_slow_common(struct rtmutex *rtmutex, bool timed, uint64_t ticks) } if (error) { + rtmutex_inc_sc(RTMUTEX_SC_WAIT_ERRORS); + /* * Keep in mind more than one thread may have timed out on waiting. * These threads aren't considered waiters, making the turnstile @@ -91,17 +145,23 @@ rtmutex_lock_slow_common(struct rtmutex *rtmutex, bool timed, uint64_t ticks) owner = atomic_load(&rtmutex->owner, ATOMIC_RELAXED); if (owner & RTMUTEX_CONTENDED) { + rtmutex_inc_sc(RTMUTEX_SC_ERROR_DOWNGRADES); owner &= RTMUTEX_OWNER_MASK; atomic_store(&rtmutex->owner, owner, ATOMIC_RELAXED); + } else { + rtmutex_inc_sc(RTMUTEX_SC_CANCELED_DOWNGRADES); } } goto out; } + rtmutex_inc_sc(RTMUTEX_SC_WAIT_SUCCESSES); + turnstile_own(turnstile); if (turnstile_empty(turnstile)) { + rtmutex_inc_sc(RTMUTEX_SC_DOWNGRADES); owner = atomic_swap(&rtmutex->owner, self, ATOMIC_RELAXED); assert(owner == (self | bits)); } @@ -166,3 +226,16 @@ rtmutex_unlock_slow(struct rtmutex *rtmutex) /* TODO Make private, use thread_set_priority_propagation_needed instead */ thread_propagate_priority(); } + +static int +rtmutex_setup(void) +{ + rtmutex_setup_debug(); + return 0; +} + +INIT_OP_DEFINE(rtmutex_setup, +#if RTMUTEX_DEBUG + INIT_OP_DEP(syscnt_setup, true), +#endif /* RTMUTEX_DEBUG */ + ); |