+ mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch added to -mm tree

The patch titled
     Subject: mm/page_alloc: remove the throttling logic from the page allocator
has been added to the -mm tree.  Its filename is
     mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch

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------------------------------------------------------
From: Mel Gorman <redacted>
Subject: mm/page_alloc: remove the throttling logic from the page allocator

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.

Link: https://lkml.kernel.org/r/20211022144651.19914-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <redacted>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <redacted>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Vlastimil Babka <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |   21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

--- a/mm/page_alloc.c~mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator
+++ a/mm/page_alloc.c

@@ -4791,30 +4791,11 @@ should_reclaim_retry(gfp_t gfp_mask, uns
 		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

_

Patches currently in -mm which might be from mgorman@techsingularity.net are

mm-vmscan-throttle-reclaim-until-some-writeback-completes-if-congested.patch
mm-vmscan-throttle-reclaim-and-compaction-when-too-may-pages-are-isolated.patch
mm-vmscan-throttle-reclaim-when-no-progress-is-being-made.patch
mm-writeback-throttle-based-on-page-writeback-instead-of-congestion.patch
mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch
mm-vmscan-centralise-timeout-values-for-reclaim_throttle.patch
mm-vmscan-increase-the-timeout-if-page-reclaim-is-not-making-progress.patch
mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress.patch