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From:   Zi Yan <zi.yan@sent.com>
To:     linux-mm@kvack.org
Cc:     Zi Yan <ziy@nvidia.com>, David Hildenbrand <david@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Yang Shi <shy828301@gmail.com>,
        David Rientjes <rientjes@google.com>,
        James Houghton <jthoughton@google.com>,
        Mike Rapoport <rppt@kernel.org>,
        Muchun Song <songmuchun@bytedance.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v1 05/12] fs: proc: use pageblock_nr_pages for reschedule period in read_kcore()
Date:   Wed, 21 Sep 2022 21:12:45 -0400
Message-Id: <20220922011252.2266780-6-zi.yan@sent.com>
In-Reply-To: <20220922011252.2266780-1-zi.yan@sent.com>
References: <20220922011252.2266780-1-zi.yan@sent.com>
Reply-To: Zi Yan <ziy@nvidia.com>
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From: Zi Yan <ziy@nvidia.com>

MAX_ORDER_NR_PAGES can be increased when it becomes a boot time parameter
in later commits. To make sure read_kcore() reschedule its work in a
constant period, use pageblock_nr_pages instead for reschedule period,
since pageblock_nr_pages is a constant and either the same or half of
MAX_ORDER_NR_PAGES.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Ying Chen <chenying.kernel@bytedance.com>
Cc: Feng Zhou <zhoufeng.zf@bytedance.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
 fs/proc/kcore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index dff921f7ca33..7dc09d211b48 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -491,7 +491,7 @@ read_kcore(struct file *file, char __user *buffer, size=
_t buflen, loff_t *fpos)
 			}
 		}
=20
-		if (page_offline_frozen++ % MAX_ORDER_NR_PAGES =3D=3D 0) {
+		if (page_offline_frozen++ % pageblock_nr_pages =3D=3D 0) {
 			page_offline_thaw();
 			cond_resched();
 			page_offline_freeze();
--=20
2.35.1