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From:   Huang Ying <ying.huang@intel.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Huang Ying <ying.huang@intel.com>,
        Xin Hao <xhao@linux.alibaba.com>, Zi Yan <ziy@nvidia.com>,
        Yang Shi <shy828301@gmail.com>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Oscar Salvador <osalvador@suse.de>,
        Alistair Popple <apopple@nvidia.com>
Subject: [PATCH 2/2] migrate_pages_batch: code cleanup: remove is_large
Date:   Tue,  9 May 2023 10:20:14 +0800
Message-Id: <20230509022014.380493-2-ying.huang@intel.com>
In-Reply-To: <20230509022014.380493-1-ying.huang@intel.com>
References: <20230509022014.380493-1-ying.huang@intel.com>
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Precedence: bulk

Previously, in migrate_pages_batch we need to track whether the source
folio is large/THP before splitting.  So is_large is used to cache
folio_test_large() result.  Now, we don't need that variable any more
because we don't count retrying and failure of large folios (only
counting that of THP folios).  So, in this patch, is_large is removed
to simplify the code.

This is just code cleanup, no functionality changes are expected.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Xin Hao <xhao@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Alistair Popple <apopple@nvidia.com>
---
 mm/migrate.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 10709aed76d3..2ac927a82bbc 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1618,7 +1618,6 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
 	int nr_failed = 0;
 	int nr_retry_pages = 0;
 	int pass = 0;
-	bool is_large = false;
 	bool is_thp = false;
 	struct folio *folio, *folio2, *dst = NULL, *dst2;
 	int rc, rc_saved = 0, nr_pages;
@@ -1635,13 +1634,7 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
 		nr_retry_pages = 0;
 
 		list_for_each_entry_safe(folio, folio2, from, lru) {
-			/*
-			 * Large folio statistics is based on the source large
-			 * folio. Capture required information that might get
-			 * lost during migration.
-			 */
-			is_large = folio_test_large(folio);
-			is_thp = is_large && folio_test_pmd_mappable(folio);
+			is_thp = folio_test_large(folio) && folio_test_pmd_mappable(folio);
 			nr_pages = folio_nr_pages(folio);
 
 			cond_resched();
@@ -1688,7 +1681,7 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
 				nr_failed++;
 				stats->nr_thp_failed += is_thp;
 				/* Large folio NUMA faulting doesn't split to retry. */
-				if (is_large && !nosplit) {
+				if (folio_test_large(folio) && !nosplit) {
 					int ret = try_split_folio(folio, split_folios);
 
 					if (!ret) {
-- 
2.39.2