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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5E272C43458 for ; Sat, 27 Jun 2026 02:02:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2682B6B0088; Fri, 26 Jun 2026 22:02:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1F1CD6B008A; Fri, 26 Jun 2026 22:02:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 093436B0092; Fri, 26 Jun 2026 22:02:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id CA4946B0088 for ; Fri, 26 Jun 2026 22:02:49 -0400 (EDT) Received: from smtpin25.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 349881A0634 for ; Sat, 27 Jun 2026 02:02:49 +0000 (UTC) X-FDA: 84924044058.25.C133ED2 Received: from canpmsgout07.his.huawei.com (canpmsgout07.his.huawei.com [113.46.200.222]) by imf20.hostedemail.com (Postfix) with ESMTP id B57AE1C0002 for ; Sat, 27 Jun 2026 02:02:45 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=gjMnZimu; spf=pass (imf20.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 113.46.200.222 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782525767; b=G7P17W6ub4QWMglpWp8NeTc8H4ZKTClt5BbgoTaVK+85ZKYdggvt55sQTLvbx+x6O+C9Zz 91I7yWXzeISwG8F/PUXlQpUPAGsmecOZHF6ow/QRPvfRUKWHrdMTepY90asAF9rIZmT33s 01T0KaSw93Ujb9kX5DNVTrqBegXUyQA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782525767; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=wSo8Q+yLQGdZX1UOIghquAO1yLazKdYABRmFO2rMjFc=; b=OeooKVpRx4UmtjvhWRQsSh2WQC6iJJcU1zcWYiCigWSIFIiDKeMJuXrmuvIek5OY7yLZna ThORWbaRdtX6uFXVA5dNPJxbe4DiJbbGZ936RAPPPxeajlM6agQJiQv5embFU9vTAHL/Hg JCN/DCEgNLXd44cbAtgnWyVaURnFIm8= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=gjMnZimu; spf=pass (imf20.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 113.46.200.222 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=wSo8Q+yLQGdZX1UOIghquAO1yLazKdYABRmFO2rMjFc=; b=gjMnZimu8islHmhOjSiPKaopV4mPDV5GIVFK9eHpwb8tSQCsQYzwGkCmDZgOFzk0ZMd4jit9i mcOIiLobn3eMFhWyIE6AKjr7/pZEwZzVstj0U+o1ILi9XN76ciTATwOAycElahJMKwR0dwP0lR3 VKTI7nzJ4WIf19ahhPIVYjc= Received: from mail.maildlp.com (unknown [172.19.163.127]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4gnFv15vQrzLlT9; Sat, 27 Jun 2026 09:53:33 +0800 (CST) Received: from dggpemf100008.china.huawei.com (unknown [7.185.36.138]) by mail.maildlp.com (Postfix) with ESMTPS id D12A840572; Sat, 27 Jun 2026 10:02:40 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemf100008.china.huawei.com (7.185.36.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 27 Jun 2026 10:02:39 +0800 Message-ID: <13baa0b0-4b4f-49b2-a7d8-2a0eea63689a@huawei.com> Date: Sat, 27 Jun 2026 10:02:38 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/4] mm: mincore: use walk_page_range_vma() in do_mincore() To: "David Hildenbrand (Arm)" , Andrew Morton , Alistair Popple , Gregory Price CC: Pedro Falcato , Zi Yan , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Suren Baghdasaryan , References: <20260618092845.3905740-1-wangkefeng.wang@huawei.com> <20260618092845.3905740-2-wangkefeng.wang@huawei.com> <42e167b2-5676-45fd-8f3a-738d2f4f6623@huawei.com> <20260624193852.2a1ac8a187978e4baa75f47e@linux-foundation.org> <1b34ac03-edf7-4219-a334-1e7b7292129b@huawei.com> Content-Language: en-US From: Kefeng Wang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To dggpemf100008.china.huawei.com (7.185.36.138) X-Rspamd-Queue-Id: B57AE1C0002 X-Stat-Signature: 7bihm4bbptb6qucbaju3jfhkpefboira X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1782525765-937932 X-HE-Meta: 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 b23RCTi+ Qnp9gmOBHcuO2h9qJDetlfzuRlIQT/lir8g5jekOdk2cSsjsoNDPvjtYQdYKlE+PgnF7WDSSnsvmwyQI/39JSmBByT4ppA/M+n6GsrnF2JG2xevVAWKWiUiZ+nB8GCyhKlRU2Z+bKj3n4Qrw+g9bcwoEgYFs1Y80KSJoCDmEeSp6aphjHupPnIV/3UBGFKz3IQrm6BkKCNVn+YfwJkS00WHpnTYPWVUeva6pJYD5kRRcS2hNVh3xRM02YrlcAEPzRA66A59+0yvsqTSjhxnjLrMKdAtnGwlBC6v/5HwNaXI0p9WkFaCOtr/ASahXJX8+5aQBsmddGX4Y6ThZf1d0DYaG1rgHtOruIIypW3msNz7KO7WV/ZbSarTSgLC6ZR4SZMUUttu4ItGJv+PGWzj7xDpNqEn3pj7FkMDgQUNARv7spl10UVtTpNViPgapTwiFRSpGfdDqnhzjDdSoI7Kx47sZcXw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/26/2026 11:58 PM, David Hildenbrand (Arm) wrote: > On 6/26/26 17:21, Kefeng Wang wrote: >> >> >> On 6/25/2026 10:38 AM, Andrew Morton wrote: >>> On Mon, 22 Jun 2026 11:23:11 +0800 Kefeng Wang >>> wrote: >>> >>>> >>>> Hope Andrew can fix the comments when pickup patches. >>> >>> I added this: >>> >>> --- a/mm/mincore.c~mm-mincore-use-walk_page_range_vma-in-do_mincore-fix >>> +++ a/mm/mincore.c >>> @@ -261,12 +261,7 @@ static long do_mincore(unsigned long add >>>       } >>>         /* >>> -     * walk_page_range_vma() does not call walk_page_test(), which >>> -     * handles VM_PFNMAP VMA by invoking ->pte_hole() to skip the >>> -     * page table walk. Without this check, PFNMAP PTEs would be >>> -     * treated as present by mincore_pte_range(), changing the returned >>> -     * residency status from the historical "not resident" to "resident". >>> -     * Handle VM_PFNMAP explicitly to preserve the original behavior. >>> +     * mincore historically reports PFNMAP mappings as non-resident. >>>        */ >>>       if (vma->vm_flags & VM_PFNMAP) { >>>           __mincore_unmapped_range(addr, end, vma, vec); >>> _ >>> >> >> Thanks. >> >>> >>> Sashiko is OK with your patchset, but it might have found four(!) >>> pre-existing issues: >>> >>>     https://sashiko.dev/#/patchset/20260618092845.3905740-1- >>> wangkefeng.wang@huawei.com >>> >> >> Sorry for the late, this is pre-existing issue, I am not familiar with >> zone devices, so just focus on my changes and the subsequent >> changes related to mincore.. After a quick review, most of them are not >> issues based on my understanding. >> >> + CC Alistair and Gregroy for migrate_device.c, also Zi could you help >> to check it? >> >> 1. mlock.c, ACTION_AGAIN >> 2. migrate_device.c, goto again array overrun / double counting >> 3. migrate_device.c, softleaf_to_folio VM_WARN >> 4. migrate_device.c, pte_pfn / pte_dirty on non-present PTE >> >> I think issue 4 is real issue, a quick fix is >> >> diff --git a/mm/migrate_device.c b/mm/migrate_device.c >> index 554754eb26ff..3ccc4fc1015c 100644 >> --- a/mm/migrate_device.c >> +++ b/mm/migrate_device.c >> @@ -401,7 +401,8 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, >>                         bool anon_exclusive; >>                         pte_t swp_pte; >> >> -                       flush_cache_page(vma, addr, pte_pfn(pte)); >> +                       if (pte_present(pte)) >> +                               flush_cache_page(vma, addr, pte_pfn(pte)); >>                         anon_exclusive = folio_test_anon(folio) && >>                                           PageAnonExclusive(page); > > That looks reasonable. > >>                         if (anon_exclusive) { >> @@ -422,8 +423,12 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, >>                         migrate->cpages++; >> >>                         /* Set the dirty flag on the folio now the pte is gone. */ >> -                       if (pte_dirty(pte)) >> +                       if (pte_present(pte)) { >> +                               if (pte_dirty(pte)) >> +                                       folio_mark_dirty(folio); >> +                       } else if (softleaf_is_device_private_write(entry)) { >>                                 folio_mark_dirty(folio); >> +                       } > > The pte_presnt() check looks reasonable. But dirty handling is really > responsibility of the device side user. > > So likely just > > if (pte_present(pte) && pte_dirty(pte)) > folio_mark_dirty(folio); > Got it， I will send a separate fix if no more comments, thanks.