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From:   Lance Roy <ldr709@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     "Paul E. McKenney" <paulmck@linux.ibm.com>,
        Lance Roy <ldr709@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Matthew Wilcox <mawilcox@microsoft.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Vlastimil Babka <vbabka@suse.cz>, Jan Kara <jack@suse.cz>,
        Shakeel Butt <shakeelb@google.com>, linux-mm@kvack.org
Subject: [PATCH 13/16] mm: Replace spin_is_locked() with lockdep
Date:   Tue,  2 Oct 2018 22:38:59 -0700
Message-Id: <20181003053902.6910-14-ldr709@gmail.com>
In-Reply-To: <20181003053902.6910-1-ldr709@gmail.com>
References: <20181003053902.6910-1-ldr709@gmail.com>
Reply-To: Lance Roy <ldr709@gmail.com>
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lockdep_assert_held() is better suited to checking locking requirements,
since it won't get confused when someone else holds the lock. This is
also a step towards possibly removing spin_is_locked().

Signed-off-by: Lance Roy <ldr709@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <linux-mm@kvack.org>
---
 mm/khugepaged.c | 4 ++--
 mm/swap.c       | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a31d740e6cd1..80f12467ccb3 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1225,7 +1225,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 {
 	struct mm_struct *mm = mm_slot->mm;
 
-	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+	lockdep_assert_held(&khugepaged_mm_lock);
 
 	if (khugepaged_test_exit(mm)) {
 		/* free mm_slot */
@@ -1665,7 +1665,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	int progress = 0;
 
 	VM_BUG_ON(!pages);
-	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+	lockdep_assert_held(&khugepaged_mm_lock);
 
 	if (khugepaged_scan.mm_slot)
 		mm_slot = khugepaged_scan.mm_slot;
diff --git a/mm/swap.c b/mm/swap.c
index 26fc9b5f1b6c..c89eb442c0bf 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -824,8 +824,7 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
 	VM_BUG_ON_PAGE(!PageHead(page), page);
 	VM_BUG_ON_PAGE(PageCompound(page_tail), page);
 	VM_BUG_ON_PAGE(PageLRU(page_tail), page);
-	VM_BUG_ON(NR_CPUS != 1 &&
-		  !spin_is_locked(&lruvec_pgdat(lruvec)->lru_lock));
+	lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
 
 	if (!list)
 		SetPageLRU(page_tail);
-- 
2.19.0