From: "Li Xinhai" <lixinhai.lxh@gmail.com>
To: akpm <akpm@linux-foundation.org>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
kirill.shutemov <kirill.shutemov@linux.intel.com>,
"Mike Kravetz" <mike.kravetz@oracle.com>,
"Michal Hocko" <mhocko@kernel.org>
Subject: Re: [PATCH v4] mm/page_vma_mapped.c: Explicitly compare pfn for normal, hugetlbfs and THP page
Date: Tue, 14 Jan 2020 22:24:18 +0800 [thread overview]
Message-ID: <2020011422241567627913@gmail.com> (raw)
In-Reply-To: <20200113143820.3707ae928234e7abe64350a8@linux-foundation.org>
On 2020-01-14 at 06:38 Andrew Morton wrote:
>On Sat, 11 Jan 2020 10:18:05 +0000 Li Xinhai <lixinhai.lxh@gmail.com> wrote:
>
>> When check_pte, pfn of normal, hugetlbfs and THP page need be compared.
>> The current implementation apply comparison as
>> - normal 4K page: page_pfn <= pfn < page_pfn + 1
>> - hugetlbfs page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR
>> - THP page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR
>> in pfn_in_hpage. For hugetlbfs page, it should be
>> page_pfn == pfn
>
>Does this have any runtime effects?
No impaction to current behavior, just make the code clear.
>
>> Now, change pfn_in_hpage to pfn_is_match to highlight that comparison
>> is not only for THP and explicitly compare for these cases.
next prev parent reply other threads:[~2020-01-14 14:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-11 10:18 Li Xinhai
2020-01-13 22:38 ` Andrew Morton
2020-01-14 14:24 ` Li Xinhai [this message]
2020-01-14 9:25 ` Michal Hocko
2020-01-14 13:47 ` Li Xinhai
2020-01-15 9:31 ` Michal Hocko
2020-01-16 0:40 ` Mike Kravetz
2020-01-16 10:29 ` Michal Hocko
2020-09-02 22:26 ` Yang Shi
2020-09-03 8:02 ` Michal Hocko
2020-09-03 16:08 ` Yang Shi
2020-09-04 1:22 ` Yang Shi
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