From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86AB0C001E0 for ; Mon, 31 Jul 2023 11:20:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232382AbjGaLUR (ORCPT ); Mon, 31 Jul 2023 07:20:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230390AbjGaLUN (ORCPT ); Mon, 31 Jul 2023 07:20:13 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 819981704 for ; Mon, 31 Jul 2023 04:20:07 -0700 (PDT) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4RDwgl6lBszLnjT; Mon, 31 Jul 2023 19:17:23 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 31 Jul 2023 19:20:03 +0800 Message-ID: <91863dc8-1f70-ba29-b36d-9261dd594574@huawei.com> Date: Mon, 31 Jul 2023 19:20:03 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: [PATCH 2/4] mm: mremap: use flush_pmd_tlb_range() in move_normal_pmd() Content-Language: en-US To: Catalin Marinas CC: Andrew Morton , Will Deacon , Mike Kravetz , Muchun Song , Mina Almasry , , , , , , , References: <20230731074829.79309-1-wangkefeng.wang@huawei.com> <20230731074829.79309-3-wangkefeng.wang@huawei.com> From: Kefeng Wang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm100001.china.huawei.com (7.185.36.93) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/7/31 19:05, Catalin Marinas wrote: > On Mon, Jul 31, 2023 at 03:48:27PM +0800, Kefeng Wang wrote: >> Archs may need to do special things when flushing thp tlb, >> so use the more applicable flush_pud_tlb_range() instead of >> flush_tlb_range(). >> >> Fixes: 2c91bd4a4e2e ("mm: speed up mremap by 20x on large regions") >> Signed-off-by: Kefeng Wang >> --- >> mm/mremap.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/mremap.c b/mm/mremap.c >> index 11e06e4ab33b..1883205fa22b 100644 >> --- a/mm/mremap.c >> +++ b/mm/mremap.c >> @@ -284,7 +284,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, >> VM_BUG_ON(!pmd_none(*new_pmd)); >> >> pmd_populate(mm, new_pmd, pmd_pgtable(pmd)); >> - flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); >> + flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); > > I don't think that's correct for arm64. The assumption in the > flush_p*d_tlb_range() was that they are called only for block mappings > at that p*d level (and we use FEAT_TTL on arm64 indicating that the leaf > level is level 2 for pmd, 1 for pud). IIUC move_normal_pmd() is only > called for table pmds which would have a leaf level of 3 (the pte). oops, yes, this is for NORMAL_PMD case, not HPAGE_PMD, please ignore patch 2/3. > > Same for the next patch doing the equivalent for the pud. >