diff options
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 42 |
1 files changed, 34 insertions, 8 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 84fd2a8f56aa..6657bcbd2064 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -205,6 +205,23 @@ struct pool_workqueue { int refcnt; /* L: reference count */ int nr_in_flight[WORK_NR_COLORS]; /* L: nr of in_flight works */ + + /* + * nr_active management and WORK_STRUCT_INACTIVE: + * + * When pwq->nr_active >= max_active, new work item is queued to + * pwq->inactive_works instead of pool->worklist and marked with + * WORK_STRUCT_INACTIVE. + * + * All work items marked with WORK_STRUCT_INACTIVE do not participate + * in pwq->nr_active and all work items in pwq->inactive_works are + * marked with WORK_STRUCT_INACTIVE. But not all WORK_STRUCT_INACTIVE + * work items are in pwq->inactive_works. Some of them are ready to + * run in pool->worklist or worker->scheduled. Those work itmes are + * only struct wq_barrier which is used for flush_work() and should + * not participate in pwq->nr_active. For non-barrier work item, it + * is marked with WORK_STRUCT_INACTIVE iff it is in pwq->inactive_works. + */ int nr_active; /* L: nr of active works */ int max_active; /* L: max active works */ struct list_head inactive_works; /* L: inactive works */ @@ -1171,19 +1188,21 @@ static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, unsigned long work_ { int color = get_work_color(work_data); - /* uncolored work items don't participate in flushing or nr_active */ + if (!(work_data & WORK_STRUCT_INACTIVE)) { + pwq->nr_active--; + if (!list_empty(&pwq->inactive_works)) { + /* one down, submit an inactive one */ + if (pwq->nr_active < pwq->max_active) + pwq_activate_first_inactive(pwq); + } + } + + /* uncolored work items don't participate in flushing */ if (color == WORK_NO_COLOR) goto out_put; pwq->nr_in_flight[color]--; - pwq->nr_active--; - if (!list_empty(&pwq->inactive_works)) { - /* one down, submit an inactive one */ - if (pwq->nr_active < pwq->max_active) - pwq_activate_first_inactive(pwq); - } - /* is flush in progress and are we at the flushing tip? */ if (likely(pwq->flush_color != color)) goto out_put; @@ -1283,6 +1302,10 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork, debug_work_deactivate(work); /* + * A cancelable inactive work item must be in the + * pwq->inactive_works since a queued barrier can't be + * canceled (see the comments in insert_wq_barrier()). + * * An inactive work item cannot be grabbed directly because * it might have linked NO_COLOR work items which, if left * on the inactive_works list, will confuse pwq->nr_active @@ -2675,6 +2698,9 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, barr->task = current; + /* The barrier work item does not participate in pwq->nr_active. */ + work_flags |= WORK_STRUCT_INACTIVE; + /* * If @target is currently being executed, schedule the * barrier to the worker; otherwise, put it after @target. |