diff options
Diffstat (limited to 'libcilkrts/runtime/scheduler.c')
| -rw-r--r-- | libcilkrts/runtime/scheduler.c | 114 |
1 files changed, 85 insertions, 29 deletions
diff --git a/libcilkrts/runtime/scheduler.c b/libcilkrts/runtime/scheduler.c index bab6430d9db..538c43104f3 100644 --- a/libcilkrts/runtime/scheduler.c +++ b/libcilkrts/runtime/scheduler.c @@ -2,11 +2,9 @@ * ************************************************************************* * - * @copyright - * Copyright (C) 2007-2013, Intel Corporation + * Copyright (C) 2007-2016, Intel Corporation * All rights reserved. * - * @copyright * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -21,7 +19,6 @@ * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * - * @copyright * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR @@ -34,6 +31,20 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. + * + * ********************************************************************* + * + * PLEASE NOTE: This file is a downstream copy of a file mainitained in + * a repository at cilkplus.org. Changes made to this file that are not + * submitted through the contribution process detailed at + * http://www.cilkplus.org/submit-cilk-contribution will be lost the next + * time that a new version is released. Changes only submitted to the + * GNU compiler collection or posted to the git repository at + * https://bitbucket.org/intelcilkruntime/intel-cilk-runtime.git are + * not tracked. + * + * We welcome your contributions to this open source project. Thank you + * for your assistance in helping us improve Cilk Plus. * **************************************************************************/ @@ -1778,7 +1789,15 @@ static full_frame* check_for_work(__cilkrts_worker *w) if (NULL == ff) { // Punish the worker for failing to steal. // No quantum for you! - __cilkrts_yield(); + if (w->l->steal_failure_count > 30000) { + // Punish more if the worker has been doing unsuccessful steals + // for a long time. After return from the idle state, it will + // be given a grace period to react quickly. + __cilkrts_idle(); + w->l->steal_failure_count -= 300; + } else { + __cilkrts_yield(); + } w->l->steal_failure_count++; } else { // Reset steal_failure_count since there is obviously still work to @@ -1808,6 +1827,7 @@ static full_frame* search_until_work_found_or_done(__cilkrts_worker *w) ff = check_for_work(w); break; case SCHEDULE_WAIT: // go into wait-mode. + START_INTERVAL(w, INTERVAL_SCHEDULE_WAIT); CILK_ASSERT(WORKER_SYSTEM == w->l->type); // If we are about to wait, then we better not have // a frame that we should execute... @@ -1818,6 +1838,7 @@ static full_frame* search_until_work_found_or_done(__cilkrts_worker *w) // Runtime is waking up. notify_children_run(w); w->l->steal_failure_count = 0; + STOP_INTERVAL(w, INTERVAL_SCHEDULE_WAIT); break; case SCHEDULE_EXIT: // exit the scheduler. CILK_ASSERT(WORKER_USER != w->l->type); @@ -2006,9 +2027,6 @@ static void worker_scheduler_init_function(__cilkrts_worker *w) // The startup work varies, depending on the worker type. switch (w->l->type) { case WORKER_USER: - // Stop working once we've entered the scheduler. - // For user workers, INTERVAL_IN_SCHEDULER counts the time - // since we called bind_thread. break; case WORKER_SYSTEM: @@ -2022,11 +2040,6 @@ static void worker_scheduler_init_function(__cilkrts_worker *w) // Runtime is waking up. notify_children_run(w); w->l->steal_failure_count = 0; - - // For system threads, count all the time this thread is - // alive in the scheduling loop. - START_INTERVAL(w, INTERVAL_IN_SCHEDULER); - START_INTERVAL(w, INTERVAL_WORKING); break; default: __cilkrts_bug("Unknown worker %p of type %d entering scheduling loop\n", @@ -2047,8 +2060,6 @@ static void worker_scheduler_terminate_function(__cilkrts_worker *w) // A user worker should never finish by falling through the // scheduling loop. CILK_ASSERT(WORKER_USER != w->l->type); - STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); - STOP_INTERVAL(w, INTERVAL_IN_SCHEDULER); } /** @@ -2060,30 +2071,36 @@ static void worker_scheduler_terminate_function(__cilkrts_worker *w) */ static void worker_scheduler_function(__cilkrts_worker *w) { + START_INTERVAL(w, INTERVAL_INIT_WORKER); worker_scheduler_init_function(w); - + STOP_INTERVAL(w, INTERVAL_INIT_WORKER); + // The main scheduling loop body. while (!w->g->work_done) { - // Set intervals. Now we are in the runtime instead of working. - START_INTERVAL(w, INTERVAL_IN_RUNTIME); - STOP_INTERVAL(w, INTERVAL_WORKING); - // Execute the "body" of the scheduling loop, and figure // out the fiber to jump to next. + START_INTERVAL(w, INTERVAL_SCHED_LOOP); cilk_fiber* fiber_to_resume = worker_scheduling_loop_body(w->l->scheduling_fiber, w); - + STOP_INTERVAL(w, INTERVAL_SCHED_LOOP); + if (fiber_to_resume) { // Suspend the current fiber and resume next one. NOTE_INTERVAL(w, INTERVAL_SUSPEND_RESUME_OTHER); + + // Whenever we jump to resume user code, we stop being in + // the runtime, and start working. STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); START_INTERVAL(w, INTERVAL_WORKING); cilk_fiber_suspend_self_and_resume_other(w->l->scheduling_fiber, fiber_to_resume); - // Return here only when this (scheduling) fiber is // resumed (i.e., this worker wants to reenter the runtime). + + // We've already switched from WORKING to IN_RUNTIME in + // the runtime code that handles the fiber switch. Thus, at + // this point we are IN_RUNTIME already. } } @@ -2183,6 +2200,8 @@ NORETURN __cilkrts_c_sync(__cilkrts_worker *w, __cilkrts_stack_frame *sf_at_sync) { full_frame *ff; + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); // Claim: This read of w->l->frame_ff can occur without // holding the worker lock because when w has reached a sync @@ -2343,6 +2362,11 @@ void __cilkrts_c_THE_exception_check(__cilkrts_worker *w, int stolen_p; __cilkrts_stack_frame *saved_sf = NULL; + // For the exception check, stop working and count as time in + // runtime. + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); + START_INTERVAL(w, INTERVAL_THE_EXCEPTION_CHECK); BEGIN_WITH_WORKER_LOCK(w) { @@ -2410,6 +2434,11 @@ void __cilkrts_c_THE_exception_check(__cilkrts_worker *w, else { NOTE_INTERVAL(w, INTERVAL_THE_EXCEPTION_CHECK_USELESS); + + // If we fail the exception check and return, then switch back + // to working. + STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); + START_INTERVAL(w, INTERVAL_WORKING); return; } } @@ -2419,6 +2448,9 @@ NORETURN __cilkrts_exception_from_spawn(__cilkrts_worker *w, __cilkrts_stack_frame *returning_sf) { full_frame *ff = w->l->frame_ff; + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); + // This is almost the same as THE_exception_check, except // the detach didn't happen, we don't need to undo the tail // update. @@ -2551,6 +2583,10 @@ __cilkrts_stack_frame *simulate_pop_tail(__cilkrts_worker *w) void __cilkrts_return(__cilkrts_worker *w) { full_frame *ff, *parent_ff; + + // Count time during the return as in the runtime. + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); START_INTERVAL(w, INTERVAL_RETURNING); BEGIN_WITH_WORKER_LOCK_OPTIONAL(w) { @@ -2604,6 +2640,8 @@ void __cilkrts_return(__cilkrts_worker *w) } END_WITH_WORKER_LOCK_OPTIONAL(w); STOP_INTERVAL(w, INTERVAL_RETURNING); + STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); + START_INTERVAL(w, INTERVAL_WORKING); } static void __cilkrts_unbind_thread() @@ -2619,13 +2657,10 @@ static void __cilkrts_unbind_thread() if (w) { g = w->g; - // If there's only 1 worker, the counts will be stopped in - // __cilkrts_scheduler - if (g->P > 1) - { - STOP_INTERVAL(w, INTERVAL_WORKING); - STOP_INTERVAL(w, INTERVAL_IN_SCHEDULER); - } + + // Matches the START in bind_thread in cilk-abi.c. + STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); + STOP_INTERVAL(w, INTERVAL_IN_SCHEDULER); __cilkrts_set_tls_worker(0); @@ -2658,6 +2693,11 @@ void __cilkrts_c_return_from_initial(__cilkrts_worker *w) { struct cilkred_map *rm; + // When we are returning from the initial frame, switch from + // INTERVAL_WORKING into INTERVAL_IN_RUNTIME. + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); + /* This is only called on a user thread worker. */ CILK_ASSERT(w->l->type == WORKER_USER); @@ -3629,6 +3669,11 @@ slow_path_reductions_for_spawn_return(__cilkrts_worker *w, // We have reductions to execute (and we can't hold locks). __cilkrts_frame_unlock(w, ff->parent); + // After we've released the lock, start counting time as + // WORKING again. + STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); + START_INTERVAL(w, INTERVAL_WORKING); + // Merge all reducers into the left map. left_map = repeated_merge_reducer_maps(&w, left_map, @@ -3649,6 +3694,9 @@ slow_path_reductions_for_spawn_return(__cilkrts_worker *w, ff->pending_exception = w->l->pending_exception; w->l->pending_exception = NULL; + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); + // Lock ff->parent for the next loop around. __cilkrts_frame_lock(w, ff->parent); @@ -3809,6 +3857,11 @@ slow_path_reductions_for_sync(__cilkrts_worker *w, return w; } } END_WITH_FRAME_LOCK(w, ff); + + // After we've released the lock, start counting time as + // WORKING again. + STOP_INTERVAL(w, INTERVAL_IN_RUNTIME); + START_INTERVAL(w, INTERVAL_WORKING); // If we get here, we have a nontrivial reduction to execute. middle_map = repeated_merge_reducer_maps(&w, @@ -3816,6 +3869,9 @@ slow_path_reductions_for_sync(__cilkrts_worker *w, middle_map); verify_current_wkr(w); + STOP_INTERVAL(w, INTERVAL_WORKING); + START_INTERVAL(w, INTERVAL_IN_RUNTIME); + // Save any exceptions generated because of the reduction // process. These get merged the next time around the // loop. |