linux-kernel - [Patch v2 6/7] mm/hugetlb: return non-isolated page in the loop instead of break and check

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Message-Id: <20200828033242.8787-7-richard.weiyang@linux.alibaba.com>
Date:   Fri, 28 Aug 2020 11:32:41 +0800
From:   Wei Yang <richard.weiyang@...ux.alibaba.com>
To:     mike.kravetz@...cle.com, akpm@...ux-foundation.org
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org, bhe@...hat.com,
        Wei Yang <richard.weiyang@...ux.alibaba.com>
Subject: [Patch v2 6/7] mm/hugetlb: return non-isolated page in the loop instead of break and check

Function dequeue_huge_page_node_exact() iterates the free list and
return the first non-isolated one.

Instead of break and check the loop variant, we could return in the loop
directly. This could reduce some redundant check.

Signed-off-by: Wei Yang <richard.weiyang@...ux.alibaba.com>
Reviewed-by: Mike Kravetz <mike.kravetz@...cle.com>
---
 mm/hugetlb.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5a71cb7acf6b..6ad365dd1e96 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1033,20 +1033,18 @@ static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
 {
 	struct page *page;
 
-	list_for_each_entry(page, &h->hugepage_freelists[nid], lru)
-		if (!PageHWPoison(page))
-			break;
-	/*
-	 * if 'non-isolated free hugepage' not found on the list,
-	 * the allocation fails.
-	 */
-	if (&h->hugepage_freelists[nid] == &page->lru)
-		return NULL;
-	list_move(&page->lru, &h->hugepage_activelist);
-	set_page_refcounted(page);
-	h->free_huge_pages--;
-	h->free_huge_pages_node[nid]--;
-	return page;
+	list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
+		if (PageHWPoison(page))
+			continue;
+
+		list_move(&page->lru, &h->hugepage_activelist);
+		set_page_refcounted(page);
+		h->free_huge_pages--;
+		h->free_huge_pages_node[nid]--;
+		return page;
+	}
+
+	return NULL;
 }
 
 static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid,
-- 
2.20.1 (Apple Git-117)