diff options
Diffstat (limited to 'sys/kern/kern_umtx.c')
| -rw-r--r-- | sys/kern/kern_umtx.c | 67 |
1 files changed, 0 insertions, 67 deletions
diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c index 2640278..6df3ce7 100644 --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -193,13 +193,6 @@ static int umtx_pi_allocated; SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW, 0, "umtx debug"); SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD, &umtx_pi_allocated, 0, "Allocated umtx_pi"); -SYSCTL_DECL(_kern_threads); -static int umtx_dflt_spins = 0; -SYSCTL_INT(_kern_threads, OID_AUTO, umtx_dflt_spins, CTLFLAG_RW, - &umtx_dflt_spins, 0, "default umtx spin count"); -static int umtx_max_spins = 3000; -SYSCTL_INT(_kern_threads, OID_AUTO, umtx_max_spins, CTLFLAG_RW, - &umtx_max_spins, 0, "max umtx spin count"); static void umtxq_sysinit(void *); static void umtxq_hash(struct umtx_key *key); @@ -1025,33 +1018,16 @@ _do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags, int timo, { struct umtx_q *uq; uint32_t owner, old, id; -#ifdef SMP - int spincount; -#endif int error = 0; id = td->td_tid; uq = td->td_umtxq; -#ifdef SMP - if (smp_cpus > 1) { - spincount = fuword32(&m->m_spincount); - if (spincount == 0) - spincount = umtx_dflt_spins; - if (spincount > umtx_max_spins) - spincount = umtx_max_spins; - } else - spincount = 0; -#endif - /* * Care must be exercised when dealing with umtx structure. It * can fault on any access. */ for (;;) { -#ifdef SMP -try_unowned: -#endif /* * Try the uncontested case. This should be done in userland. */ @@ -1067,9 +1043,6 @@ try_unowned: /* If no one owns it but it is contested try to acquire it. */ if (owner == UMUTEX_CONTESTED) { -#ifdef SMP -try_contested: -#endif owner = casuword32(&m->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); @@ -1091,46 +1064,6 @@ try_contested: if (try != 0) return (EBUSY); -#ifdef SMP - if (spincount > 0 && (owner & ~UMUTEX_CONTESTED) != id) { - int i, found = 0; - struct pcpu *pcpu = NULL; - - /* Look for a cpu the owner is running on */ - for (i = 0; i < MAXCPU; i++) { - if (CPU_ABSENT(i)) - continue; - pcpu = pcpu_find(i); - if ((owner & ~UMUTEX_CONTESTED) == pcpu->pc_curtid) { - found = 1; - break; - } - } - - if (__predict_false(!found)) - goto end_spin; - - while ((owner & ~UMUTEX_CONTESTED) == pcpu->pc_curtid && - (owner & ~UMUTEX_CONTESTED) != id) { - if (--spincount <= 0) - break; - if ((td->td_flags & - (TDF_NEEDRESCHED|TDF_ASTPENDING|TDF_NEEDSIGCHK)) || - P_SHOULDSTOP(td->td_proc)) - break; - owner = fuword32(__DEVOLATILE(uint32_t *, &m->m_owner)); - if (owner == UMUTEX_UNOWNED) - goto try_unowned; - if (owner == UMUTEX_CONTESTED) - goto try_contested; - cpu_spinwait(); - } - } -end_spin: - spincount = 0; - -#endif - /* * If we caught a signal, we have retried and now * exit immediately. |
