diff options
Diffstat (limited to 'erts/emulator/beam/erl_process.c')
-rw-r--r-- | erts/emulator/beam/erl_process.c | 105 |
1 files changed, 74 insertions, 31 deletions
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c index dd8bc9a698..adea745471 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -353,6 +353,7 @@ struct erts_system_monitor_flags_t erts_system_monitor_flags; /* system performance monitor */ Eterm erts_system_profile; struct erts_system_profile_flags_t erts_system_profile_flags; +int erts_system_profile_ts_type = ERTS_TRACE_FLG_NOW_TIMESTAMP; #if ERTS_MAX_PROCESSES > 0x7fffffff #error "Need to store process_count in another type" @@ -6461,9 +6462,6 @@ suspend_process(Process *c_p, Process *p) if (suspended) { - ASSERT(!(ERTS_PSFLG_RUNNING & state) - || p == erts_get_current_process()); - if (suspended > 0 && erts_system_profile_flags.runnable_procs) { /* 'state' is before our change... */ @@ -8410,9 +8408,8 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks, resume_process(rp, rp_locks); } else { - rp = erts_pid2proc(c_p, c_p_locks|ERTS_PROC_LOCK_STATUS, - pid, pid_locks|ERTS_PROC_LOCK_STATUS); + pid, ERTS_PROC_LOCK_STATUS); if (!rp) { c_p->flags &= ~F_P2PNR_RESCHED; @@ -8421,40 +8418,84 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks, ASSERT(!(c_p->flags & F_P2PNR_RESCHED)); - if (suspend) { - if (suspend_process(c_p, rp)) - goto done; - } - else { - if (!((ERTS_PSFLG_RUNNING|ERTS_PSFLG_RUNNING_SYS) - & erts_smp_atomic32_read_acqb(&rp->state))) - goto done; + /* + * Suspend the other process in order to prevent + * it from being selected for normal execution. + * This will however not prevent it from being + * selected for execution of a system task. If + * it is selected for execution of a system task + * we might be blocked for quite a while if the + * try-lock below fails. That is, there is room + * for improvement here... + */ - } + if (!suspend_process(c_p, rp)) { + /* Other process running */ - /* Other process running */ + ASSERT(ERTS_PSFLG_RUNNING + & erts_smp_atomic32_read_nob(&rp->state)); - /* - * If we got pending suspenders and suspend ourselves waiting - * to suspend another process we might deadlock. - * In this case we have to yield, be suspended by - * someone else and then do it all over again. - */ - if (!c_p->pending_suspenders) { - /* Mark rp pending for suspend by c_p */ - add_pend_suspend(rp, c_p->common.id, handle_pend_sync_suspend); - ASSERT(is_nil(c_p->suspendee)); + running: - /* Suspend c_p; when rp is suspended c_p will be resumed. */ - suspend_process(c_p, c_p); - c_p->flags |= F_P2PNR_RESCHED; + /* + * If we got pending suspenders and suspend ourselves waiting + * to suspend another process we might deadlock. + * In this case we have to yield, be suspended by + * someone else and then do it all over again. + */ + if (!c_p->pending_suspenders) { + /* Mark rp pending for suspend by c_p */ + add_pend_suspend(rp, c_p->common.id, handle_pend_sync_suspend); + ASSERT(is_nil(c_p->suspendee)); + + /* Suspend c_p; when rp is suspended c_p will be resumed. */ + suspend_process(c_p, c_p); + c_p->flags |= F_P2PNR_RESCHED; + } + /* Yield (caller is assumed to yield immediately in bif). */ + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS); + rp = ERTS_PROC_LOCK_BUSY; + } + else { + ErtsProcLocks need_locks = pid_locks & ~ERTS_PROC_LOCK_STATUS; + if (need_locks && erts_smp_proc_trylock(rp, need_locks) == EBUSY) { + if (ERTS_PSFLG_RUNNING_SYS + & erts_smp_atomic32_read_nob(&rp->state)) { + /* Executing system task... */ + resume_process(rp, ERTS_PROC_LOCK_STATUS); + goto running; + } + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS); + /* + * If we are unlucky, the process just got selected for + * execution of a system task. In this case we may be + * blocked here for quite a while... Execution of system + * tasks are fortunately quite rare events. We try to + * avoid this by checking if it is in a state executing + * system tasks (above), but it will not prevent all + * scenarios for a long block here... + */ + rp = erts_pid2proc(c_p, c_p_locks|ERTS_PROC_LOCK_STATUS, + pid, pid_locks|ERTS_PROC_LOCK_STATUS); + if (!rp) + goto done; + } + + /* + * The previous suspend has prevented the process + * from being selected for normal execution regardless + * of locks held or not held on it... + */ + ASSERT(!(ERTS_PSFLG_RUNNING + & erts_smp_atomic32_read_nob(&rp->state))); + + if (!suspend) + resume_process(rp, pid_locks|ERTS_PROC_LOCK_STATUS); } - /* Yield (caller is assumed to yield immediately in bif). */ - erts_smp_proc_unlock(rp, pid_locks|ERTS_PROC_LOCK_STATUS); - rp = ERTS_PROC_LOCK_BUSY; } done: + if (rp && rp != ERTS_PROC_LOCK_BUSY && !(pid_locks & ERTS_PROC_LOCK_STATUS)) erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS); if (unlock_c_p_status) @@ -9698,6 +9739,8 @@ Process *schedule(Process *p, int calls) erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS); + state = erts_smp_atomic32_read_nob(&p->state); + if (erts_sched_stat.enabled) { int prio; UWord old = ERTS_PROC_SCHED_ID(p, |