linux-kernel - [PATCH v2] mm/hugetlb: remove redundant reservation check condition in alloc_huge

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Message-ID: <20210301104726.45159-1-linmiaohe@huawei.com>
Date:   Mon, 1 Mar 2021 05:47:26 -0500
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>, <mike.kravetz@...cle.com>
CC:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linmiaohe@...wei.com>
Subject: [PATCH v2] mm/hugetlb: remove redundant reservation check condition in alloc_huge_page()

vma_resv_map(vma) checks if a reserve map is associated with the vma.  The
routine vma_needs_reservation() will check vma_resv_map(vma) and return 1
if no reserv map is present.  map_chg is set to the return value of
vma_needs_reservation().  Therefore, !vma_resv_map(vma) is redundant in the
expression:
	map_chg || avoid_reserve || !vma_resv_map(vma);
Remove the redundant check.

[Thanks Mike Kravetz for reshaping this commit message!]

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 60c67eb016f7..060005b868cf 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2314,7 +2314,7 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
 
 	/* If this allocation is not consuming a reservation, charge it now.
 	 */
-	deferred_reserve = map_chg || avoid_reserve || !vma_resv_map(vma);
+	deferred_reserve = map_chg || avoid_reserve;
 	if (deferred_reserve) {
 		ret = hugetlb_cgroup_charge_cgroup_rsvd(
 			idx, pages_per_huge_page(h), &h_cg);
-- 
2.19.1