diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 50 |
1 files changed, 37 insertions, 13 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 7d3fe5938e3b..599e5616b123 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1006,12 +1006,10 @@ static void handle_write_error(struct address_space *mapping, unlock_page(page); } -void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason, - long timeout) +void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason) { wait_queue_head_t *wqh = &pgdat->reclaim_wait[reason]; - long ret; - bool acct_writeback = (reason == VMSCAN_THROTTLE_WRITEBACK); + long timeout, ret; DEFINE_WAIT(wait); /* @@ -1023,17 +1021,43 @@ void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason, current->flags & (PF_IO_WORKER|PF_KTHREAD)) return; - if (acct_writeback && - atomic_inc_return(&pgdat->nr_writeback_throttled) == 1) { - WRITE_ONCE(pgdat->nr_reclaim_start, - node_page_state(pgdat, NR_THROTTLED_WRITTEN)); + /* + * These figures are pulled out of thin air. + * VMSCAN_THROTTLE_ISOLATED is a transient condition based on too many + * parallel reclaimers which is a short-lived event so the timeout is + * short. Failing to make progress or waiting on writeback are + * potentially long-lived events so use a longer timeout. This is shaky + * logic as a failure to make progress could be due to anything from + * writeback to a slow device to excessive references pages at the tail + * of the inactive LRU. + */ + switch(reason) { + case VMSCAN_THROTTLE_WRITEBACK: + timeout = HZ/10; + + if (atomic_inc_return(&pgdat->nr_writeback_throttled) == 1) { + WRITE_ONCE(pgdat->nr_reclaim_start, + node_page_state(pgdat, NR_THROTTLED_WRITTEN)); + } + + break; + case VMSCAN_THROTTLE_NOPROGRESS: + timeout = HZ/10; + break; + case VMSCAN_THROTTLE_ISOLATED: + timeout = HZ/50; + break; + default: + WARN_ON_ONCE(1); + timeout = HZ; + break; } prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); ret = schedule_timeout(timeout); finish_wait(wqh, &wait); - if (acct_writeback) + if (reason == VMSCAN_THROTTLE_WRITEBACK) atomic_dec(&pgdat->nr_writeback_throttled); trace_mm_vmscan_throttled(pgdat->node_id, jiffies_to_usecs(timeout), @@ -2318,7 +2342,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, /* wait a bit for the reclaimer. */ stalled = true; - reclaim_throttle(pgdat, VMSCAN_THROTTLE_ISOLATED, HZ/10); + reclaim_throttle(pgdat, VMSCAN_THROTTLE_ISOLATED); /* We are about to die and free our memory. Return now. */ if (fatal_signal_pending(current)) @@ -3250,7 +3274,7 @@ again: * until some pages complete writeback. */ if (sc->nr.immediate) - reclaim_throttle(pgdat, VMSCAN_THROTTLE_WRITEBACK, HZ/10); + reclaim_throttle(pgdat, VMSCAN_THROTTLE_WRITEBACK); } /* @@ -3274,7 +3298,7 @@ again: if (!current_is_kswapd() && current_may_throttle() && !sc->hibernation_mode && test_bit(LRUVEC_CONGESTED, &target_lruvec->flags)) - reclaim_throttle(pgdat, VMSCAN_THROTTLE_WRITEBACK, HZ/10); + reclaim_throttle(pgdat, VMSCAN_THROTTLE_WRITEBACK); if (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed, sc)) @@ -3346,7 +3370,7 @@ static void consider_reclaim_throttle(pg_data_t *pgdat, struct scan_control *sc) /* Throttle if making no progress at high prioities. */ if (sc->priority < DEF_PRIORITY - 2) - reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS, HZ/10); + reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS); } /* |