From: Zlatko Calusic <[email protected]> Commit 92df3a72 (mm: vmscan: throttle reclaim if encountering too many dirty pages under writeback) introduced waiting on congested zones based on a sane algorithm in shrink_inactive_list(). What this means is that there's no more need for throttling and additional heuristics in balance_pgdat(). So, let's remove it and tidy up the code.
Signed-off-by: Zlatko Calusic <[email protected]> --- include/linux/vm_event_item.h | 1 - mm/vmscan.c | 29 +---------------------------- mm/vmstat.c | 1 - 3 files changed, 1 insertion(+), 30 deletions(-) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index e84a25e..d4b7a18 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -36,7 +36,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, #endif PGINODESTEAL, SLABS_SCANNED, KSWAPD_INODESTEAL, KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY, - KSWAPD_SKIP_CONGESTION_WAIT, PAGEOUTRUN, ALLOCSTALL, PGROTATED, #ifdef CONFIG_NUMA_BALANCING NUMA_PTE_UPDATES, diff --git a/mm/vmscan.c b/mm/vmscan.c index 32fbfdb..fea5a0b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2619,7 +2619,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, int *classzone_idx) { bool pgdat_is_balanced = false; - struct zone *unbalanced_zone; int i; int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long total_scanned; @@ -2650,9 +2649,6 @@ loop_again: do { unsigned long lru_pages = 0; - int has_under_min_watermark_zone = 0; - - unbalanced_zone = NULL; /* * Scan in the highmem->dma direction for the highest @@ -2792,17 +2788,7 @@ loop_again: continue; } - if (!zone_balanced(zone, testorder, 0, end_zone)) { - unbalanced_zone = zone; - /* - * We are still under min water mark. This - * means that we have a GFP_ATOMIC allocation - * failure risk. Hurry up! - */ - if (!zone_watermark_ok_safe(zone, order, - min_wmark_pages(zone), end_zone, 0)) - has_under_min_watermark_zone = 1; - } else { + if (zone_balanced(zone, testorder, 0, end_zone)) /* * If a zone reaches its high watermark, * consider it to be no longer congested. It's @@ -2811,8 +2797,6 @@ loop_again: * speculatively avoid congestion waits */ zone_clear_flag(zone, ZONE_CONGESTED); - } - } /* @@ -2830,17 +2814,6 @@ loop_again: } /* - * OK, kswapd is getting into trouble. Take a nap, then take - * another pass across the zones. - */ - if (total_scanned && (sc.priority < DEF_PRIORITY - 2)) { - if (has_under_min_watermark_zone) - count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT); - else if (unbalanced_zone) - wait_iff_congested(unbalanced_zone, BLK_RW_ASYNC, HZ/10); - } - - /* * We do this so kswapd doesn't build up large priorities for * example when it is freeing in parallel with allocators. It * matches the direct reclaim path behaviour in terms of impact diff --git a/mm/vmstat.c b/mm/vmstat.c index 58e3da5..bb492b5 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -769,7 +769,6 @@ const char * const vmstat_text[] = { "kswapd_inodesteal", "kswapd_low_wmark_hit_quickly", "kswapd_high_wmark_hit_quickly", - "kswapd_skip_congestion_wait", "pageoutrun", "allocstall", -- 1.8.1 -- Zlatko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
