From:   Mel Gorman <mgorman@techsingularity.net>
To:     Vlastimil Babka <vbabka@suse.cz>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Maxim Levitsky <mlevitsk@redhat.com>,
        Michal Hocko <mhocko@kernel.org>,
        Pedro Falcato <pedro.falcato@gmail.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Chuyi Zhou <zhouchuyi@bytedance.com>,
        Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 3/4] mm, compaction: Finish scanning the current pageblock if requested
Date:   Wed, 25 Jan 2023 13:44:33 +0000
Message-Id: <20230125134434.18017-4-mgorman@techsingularity.net>
In-Reply-To: <20230125134434.18017-1-mgorman@techsingularity.net>
References: <20230125134434.18017-1-mgorman@techsingularity.net>
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cc->finish_pageblock is set when the current pageblock should be
rescanned but fast_find_migrateblock can select an alternative
block. Disable fast_find_migrateblock when the current pageblock
scan should be completed.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 mm/compaction.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mm/compaction.c b/mm/compaction.c
index 28711a21a8a2..4b3a0238879c 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1762,6 +1762,13 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
 	if (cc->ignore_skip_hint)
 		return pfn;
 
+	/*
+	 * If the pageblock should be finished then do not select a different
+	 * pageblock.
+	 */
+	if (cc->finish_pageblock)
+		return pfn;
+
 	/*
 	 * If the migrate_pfn is not at the start of a zone or the start
 	 * of a pageblock then assume this is a continuation of a previous
-- 
2.35.3