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Fri, 10 Jun 2022 07:28:28 +0000 (UTC) X-FDA: 79561498296.26.F6CA6A9 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf05.hostedemail.com (Postfix) with ESMTP id 69C77100063 for ; Fri, 10 Jun 2022 07:28:27 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LKCH800nnzDqlB; Fri, 10 Jun 2022 15:28:03 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 10 Jun 2022 15:28:24 +0800 Subject: Re: [v3 PATCH 3/7] mm: khugepaged: remove the redundant anon vma check From: Miaohe Lin To: Yang Shi CC: , , , , , References: <20220606214414.736109-1-shy828301@gmail.com> <20220606214414.736109-4-shy828301@gmail.com> <3f485480-9474-4401-bc4f-fb66aac1e591@huawei.com> Message-ID: <519ec924-483c-aec0-cb84-b33b25ce92b4@huawei.com> Date: Fri, 10 Jun 2022 15:28:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; 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s=arc-20220608; d=hostedemail.com; t=1654846107; a=rsa-sha256; cv=none; b=13w20tD28guqeNsl4P7v2TGB8W2fRDDTf7lXa0leNH+qQ9UhqzD6j1CVIDNKXSzf1rD5Jd 5eV/EfAeoqD5KmWT/gqdTjByW5XOo135hBtGmDQzJegLNUl76mARSieuADSSD3cXC4zyYd FoQQUtKQqq/kEeTtGwBdk0aQj8tiAUs= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf05.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspam-User: Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf05.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspamd-Server: rspam03 X-Stat-Signature: 59bd7ke95thzjrj7k89ahjjpkb1os5xk X-Rspamd-Queue-Id: 69C77100063 X-HE-Tag: 1654846107-157111 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2022/6/10 15:23, Miaohe Lin wrote: > On 2022/6/7 5:44, Yang Shi wrote: >> The hugepage_vma_check() already checked it, so remove the redundant >> check. >> >> Signed-off-by: Yang Shi >> --- >> mm/khugepaged.c | 3 --- >> 1 file changed, 3 deletions(-) >> >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index d0f8020164fc..7a5d1c1a1833 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -966,9 +966,6 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, >> return SCAN_ADDRESS_RANGE; >> if (!hugepage_vma_check(vma, vma->vm_flags)) >> return SCAN_VMA_CHECK; >> - /* Anon VMA expected */ >> - if (!vma->anon_vma || !vma_is_anonymous(vma)) >> - return SCAN_VMA_CHECK; > > Is it possible that hugepage_vma_check returns true due to the shmem check, or file thp check since > we dropped mmap_lock ? So anon vma is explicitly checked again here? I just see your discussion with similar problem. Sorry for make noise. > > Thanks! > >> return 0; >> } >> >> >