linux-kernel - [PATCH v3 15/66] mm/khugepaged: Optimize collapse_pte_mapped_thp() by using vma

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Date:   Tue, 5 Oct 2021 01:30:37 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        David Hildenbrand <david@...hat.com>,
        Douglas Gilbert <dgilbert@...erlog.com>
CC:     Song Liu <songliubraving@...com>,
        Davidlohr Bueso <dave@...olabs.net>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        David Rientjes <rientjes@...gle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Rik van Riel <riel@...riel.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v3 15/66] mm/khugepaged: Optimize collapse_pte_mapped_thp() by
 using vma_lookup()

From: "Liam R. Howlett" <Liam.Howlett@...cle.com>

vma_lookup() will walk the vma tree once and not continue to look for
the next vma.  Since the exact vma is checked below, this is a more
optimal way of searching.

Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 mm/khugepaged.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 045cc579f724..f27673c596d2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1430,7 +1430,7 @@ static int khugepaged_add_pte_mapped_thp(struct mm_struct *mm,
 void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
 {
 	unsigned long haddr = addr & HPAGE_PMD_MASK;
-	struct vm_area_struct *vma = find_vma(mm, haddr);
+	struct vm_area_struct *vma = vma_lookup(mm, haddr);
 	struct page *hpage;
 	pte_t *start_pte, *pte;
 	pmd_t *pmd, _pmd;
-- 
2.30.2