diff options
| -rw-r--r-- | kern/thread.c | 94 |
1 files changed, 46 insertions, 48 deletions
diff --git a/kern/thread.c b/kern/thread.c index 7c0ab6b2..525fa5d7 100644 --- a/kern/thread.c +++ b/kern/thread.c @@ -71,13 +71,6 @@ struct thread_rt_runq { #define THREAD_TS_INITIAL_ROUND ((unsigned long)-10) /* - * When pulling threads from a run queue, this value is used to determine - * the total number of threads to pull by dividing the number of eligible - * threads with it. - */ -#define THREAD_TS_MIGRATION_RATIO 2 - -/* * Group of threads sharing the same weight. */ struct thread_ts_group { @@ -975,74 +968,79 @@ thread_sched_ts_balance_scan(struct thread_runq *runq, } static unsigned int +thread_sched_ts_balance_pull(struct thread_runq *runq, + struct thread_runq *remote_runq, + struct thread_ts_runq *ts_runq, + unsigned int nr_pulls) +{ + struct thread *thread, *tmp; + + list_for_each_entry_safe(&ts_runq->threads, thread, tmp, ts_ctx.runq_node) { + if (thread == remote_runq->current) + continue; + + /* + * Make sure at least one thread is pulled if possible. If one or more + * thread has already been pulled, take weights into account. + */ + if ((nr_pulls != 0) + && ((runq->ts_weight + thread->ts_ctx.weight) + > (remote_runq->ts_weight - thread->ts_ctx.weight))) + break; + + thread_runq_remove(remote_runq, thread); + + /* Don't discard the work already accounted for */ + thread->ts_ctx.round = runq->ts_round; + + thread_runq_add(runq, thread); + nr_pulls++; + + if (nr_pulls == THREAD_MAX_MIGRATIONS) + break; + } + + return nr_pulls; +} + +static unsigned int thread_sched_ts_balance_migrate(struct thread_runq *runq, struct thread_runq *remote_runq, unsigned long highest_round) { - struct thread *thread, *tmp; unsigned long flags; - unsigned int i, nr_threads; + unsigned int nr_pulls; + + nr_pulls = 0; thread_preempt_disable(); flags = cpu_intr_save(); thread_runq_double_lock(runq, remote_runq); - i = 0; - if (!thread_sched_ts_balance_eligible(remote_runq, highest_round)) goto out; - nr_threads = remote_runq->ts_runq_active->nr_threads; + nr_pulls = thread_sched_ts_balance_pull(runq, remote_runq, + remote_runq->ts_runq_active, 0); - if (remote_runq->ts_round != highest_round) - nr_threads += remote_runq->ts_runq_expired->nr_threads; - - if (nr_threads == 0) + if (nr_pulls == THREAD_MAX_MIGRATIONS) goto out; - nr_threads /= THREAD_TS_MIGRATION_RATIO; - - if (nr_threads == 0) - nr_threads = 1; - else if (nr_threads > THREAD_MAX_MIGRATIONS) - nr_threads = THREAD_MAX_MIGRATIONS; - - list_for_each_entry_safe(&remote_runq->ts_runq_active->threads, - thread, tmp, ts_ctx.runq_node) { - if (thread == remote_runq->current) - continue; - - thread_runq_remove(remote_runq, thread); - thread->ts_ctx.round = runq->ts_round; - thread_runq_add(runq, thread); - i++; - - if (i == nr_threads) - goto out; - } - /* * Threads in the expired queue of a processor in round highest are * actually in round highest + 1. */ if (remote_runq->ts_round != highest_round) - list_for_each_entry_safe(&remote_runq->ts_runq_expired->threads, - thread, tmp, ts_ctx.runq_node) { - thread_runq_remove(remote_runq, thread); - thread->ts_ctx.round = runq->ts_round; - thread_runq_add(runq, thread); - i++; - - if (i == nr_threads) - goto out; - } + nr_pulls = thread_sched_ts_balance_pull(runq, remote_runq, + remote_runq->ts_runq_expired, + nr_pulls); out: spinlock_unlock(&remote_runq->lock); spinlock_unlock(&runq->lock); cpu_intr_restore(flags); thread_preempt_enable(); - return i; + return nr_pulls; } static void |