diff mbox series

[5/8] mm/page_alloc: Remove the throttling logic from the page allocator

Message ID 20211008135332.19567-6-mgorman@techsingularity.net (mailing list archive)
State New
Headers show
Series Remove dependency on congestion_wait in mm/ | expand

Commit Message

Mel Gorman Oct. 8, 2021, 1:53 p.m. UTC
The page allocator stalls based on the number of pages that are
waiting for writeback to start but this should now be redundant.
shrink_inactive_list() will wake flusher threads if the LRU tail are
unqueued dirty pages so the flusher should be active. If it fails to make
progress due to pages under writeback not being completed quickly then
it should stall on VMSCAN_THROTTLE_WRITEBACK.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 mm/page_alloc.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

Comments

Vlastimil Babka Oct. 14, 2021, 3:36 p.m. UTC | #1
On 10/8/21 15:53, Mel Gorman wrote:
> The page allocator stalls based on the number of pages that are
> waiting for writeback to start but this should now be redundant.
> shrink_inactive_list() will wake flusher threads if the LRU tail are
> unqueued dirty pages so the flusher should be active. If it fails to make
> progress due to pages under writeback not being completed quickly then
> it should stall on VMSCAN_THROTTLE_WRITEBACK.
> 
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/page_alloc.c | 21 +--------------------
>  1 file changed, 1 insertion(+), 20 deletions(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 78e538067651..8fa0109ff417 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4795,30 +4795,11 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
>  		trace_reclaim_retry_zone(z, order, reclaimable,
>  				available, min_wmark, *no_progress_loops, wmark);
>  		if (wmark) {
> -			/*
> -			 * If we didn't make any progress and have a lot of
> -			 * dirty + writeback pages then we should wait for
> -			 * an IO to complete to slow down the reclaim and
> -			 * prevent from pre mature OOM
> -			 */
> -			if (!did_some_progress) {
> -				unsigned long write_pending;
> -
> -				write_pending = zone_page_state_snapshot(zone,
> -							NR_ZONE_WRITE_PENDING);
> -
> -				if (2 * write_pending > reclaimable) {
> -					congestion_wait(BLK_RW_ASYNC, HZ/10);
> -					return true;
> -				}
> -			}
> -
>  			ret = true;
> -			goto out;
> +			break;
>  		}
>  	}
>  
> -out:
>  	/*
>  	 * Memory allocation/reclaim might be called from a WQ context and the
>  	 * current implementation of the WQ concurrency control doesn't
>
diff mbox series

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 78e538067651..8fa0109ff417 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4795,30 +4795,11 @@  should_reclaim_retry(gfp_t gfp_mask, unsigned order,
 		trace_reclaim_retry_zone(z, order, reclaimable,
 				available, min_wmark, *no_progress_loops, wmark);
 		if (wmark) {
-			/*
-			 * If we didn't make any progress and have a lot of
-			 * dirty + writeback pages then we should wait for
-			 * an IO to complete to slow down the reclaim and
-			 * prevent from pre mature OOM
-			 */
-			if (!did_some_progress) {
-				unsigned long write_pending;
-
-				write_pending = zone_page_state_snapshot(zone,
-							NR_ZONE_WRITE_PENDING);
-
-				if (2 * write_pending > reclaimable) {
-					congestion_wait(BLK_RW_ASYNC, HZ/10);
-					return true;
-				}
-			}
-
 			ret = true;
-			goto out;
+			break;
 		}
 	}
 
-out:
 	/*
 	 * Memory allocation/reclaim might be called from a WQ context and the
 	 * current implementation of the WQ concurrency control doesn't