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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EC07C001DC for ; Thu, 27 Jul 2023 11:48:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3D0A86B0074; Thu, 27 Jul 2023 07:48:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 380286B0075; Thu, 27 Jul 2023 07:48:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24A2A6B0078; Thu, 27 Jul 2023 07:48:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 17AA06B0074 for ; Thu, 27 Jul 2023 07:48:35 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id CC4D9160507 for ; Thu, 27 Jul 2023 11:48:34 +0000 (UTC) X-FDA: 81057219348.23.BD58774 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by imf12.hostedemail.com (Postfix) with ESMTP id F3A964001A for ; Thu, 27 Jul 2023 11:48:32 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=collabora.com header.s=mail header.b=VwWHBy4F; dmarc=pass (policy=quarantine) header.from=collabora.com; spf=pass (imf12.hostedemail.com: domain of usama.anjum@collabora.com designates 46.235.227.172 as permitted sender) smtp.mailfrom=usama.anjum@collabora.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1690458513; 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=YlvmQIXs/kj+YjOSseR2wQ3zbsVs1zD1kezQklMtWIo=; b=TdIu2t4MHfj6pQc1Yed7fmh7LCYhLJanSoKUZNkuDcjG6axdf7ftzaFQUwrM5m/Q3i1w/s UhGAU0bNFSkDinT45IzLo+yK7Dz91ZjjE5Vf/JtcZ7lNL9CM6cmQBL7ZWLe4GBMTY5LA1f eX7iwKP4pcmlJnOKivzQBtIhcekaXjo= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=collabora.com header.s=mail header.b=VwWHBy4F; dmarc=pass (policy=quarantine) header.from=collabora.com; spf=pass (imf12.hostedemail.com: domain of usama.anjum@collabora.com designates 46.235.227.172 as permitted sender) smtp.mailfrom=usama.anjum@collabora.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1690458513; a=rsa-sha256; cv=none; b=XAflCWZRB3xskQKmhy+T22OXZhvytr7W58NXXkdLx9MVaq2C4iiwL9h4O5i/XTmuQW+OZm KnQ4Z4B9J7DmZ+afLB1RRZifKqZfxfM1M4zM3jCTcseEw82PY460aBqkuEfEittvuR2UyM PAGp4GRrD0H90qw+cIP5BS7DYn6lA/4= Received: from [192.168.100.7] (unknown [59.103.218.24]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: usama.anjum) by madras.collabora.co.uk (Postfix) with ESMTPSA id CE4986607057; Thu, 27 Jul 2023 12:48:17 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1690458511; bh=0qxwSBYd7sM3osQHdzQ9jmOETl5u5FVEVXpJCyozE18=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=VwWHBy4Fz+Uq2ZgEVfz/g6zrk+uiQW8i288WOCqoUeKyYOZPSWRGPswZH9S4GjmjI elJ4o1Nc21T6uGBpPA4OMaU79ukYjTR6EFOZ8oQNI5xWQmuPWq8XEXZKbbwoDecklx KzPKIBcZwJ52uDt6FZzv6w6igb7g2jUHUbx/IcsmVww4JYwgu6IBR1k8X4/wy6JA7e hXzWGNky+83m0plmg16KCcnWLGNr9AjJwFzOTWwqvO39CXzVojFzPmaJraVo5xAf1n AoZswvD8VYINa6Z/6qVIh+3XCYT+VdeiuiyV03TYf/cP9aTOzIbBfmZz+MgvsgnHRJ wvuG9pLLO8YeA== Message-ID: <7f124303-660e-8350-4628-2340550637b0@collabora.com> Date: Thu, 27 Jul 2023 16:48:10 +0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Cc: Muhammad Usama Anjum , Peter Xu , David Hildenbrand , Andrew Morton , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov , Mike Rapoport , Nadav Amit , Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Matthew Wilcox , Pasha Tatashin , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com, =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Subject: Re: [PATCH v26 2/5] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs Content-Language: en-US To: =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= References: <20230727093637.1262110-1-usama.anjum@collabora.com> <20230727093637.1262110-3-usama.anjum@collabora.com> From: Muhammad Usama Anjum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: F3A964001A X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: w8r5w9pj9aenhgdyrye6j3tycykdss49 X-HE-Tag: 1690458512-433333 X-HE-Meta: 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 yLHWL1NS Ps4mLm7cZXbKCuBR5O6oGkqIO0Kt0OedvKutKaXdoKnG5dXw6b+f3leGc15oEwVpuL1RnYt8LDAP53a0fayhJjbC5SC57IfUAB27dllYNXfxmaCHeEJdCP6jenUZ0FvjDLJZtN3MCWS04b7AAfoOGZHBztan4A7eDM61K8ptxVgtE+PKVB+erY2mekYTWzaiiI8PzORDvYJK2S4k5+qBZu0wq319/wzOTChl24guaGZXMnT90D96KWhrzugOzsmD7ztkeQ54WCL6IYz54LUegv2usnzyFVrIxgqoqLVhgQ0037PQ2NEmIKOcDpXc9RHEuKzLczjPfu0KZW5A= 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 7/27/23 4:40 PM, Michał Mirosław wrote: > On Thu, 27 Jul 2023 at 11:37, Muhammad Usama Anjum > wrote: >> This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear >> the info about page table entries. The following operations are supported >> in this ioctl: >> - Get the information if the pages have Async Write-Protection enabled >> (``PAGE_IS_WPALLOWED``), have been written to (``PAGE_IS_WRITTEN``), file >> mapped (``PAGE_IS_FILE``), present (``PAGE_IS_PRESENT``), swapped >> (``PAGE_IS_SWAPPED``) or page has pfn zero (``PAGE_IS_PFNZERO``). >> - Find pages which have been written to and/or write protect >> (atomic ``PM_SCAN_WP_MATCHING + PM_SCAN_CHECK_WPASYNC``) the pages >> atomically. The (``PM_SCAN_WP_MATCHING``) is used to WP the matched >> pages. The (``PM_SCAN_CHECK_WPASYNC``) aborts the operation if >> non-Async-Write-Protected pages are found. Get is automatically performed >> if output buffer is specified. >> >> This IOCTL can be extended to get information about more PTE bits. The >> entire address range passed by user [start, end) is scanned until either >> the user provided buffer is full or max_pages have been found. >> >> Reviewed-by: Andrei Vagin >> Reviewed-by: Michał Mirosław >> Signed-off-by: Michał Mirosław >> Signed-off-by: Muhammad Usama Anjum > > Thanks for all the work! > > Small request below. > >> --- a/fs/proc/task_mmu.c >> +++ b/fs/proc/task_mmu.c > [...] >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> +static unsigned long pagemap_thp_category(pmd_t pmd) >> +{ >> + unsigned long categories = 0; >> + >> + if (pmd_present(pmd)) { >> + categories |= PAGE_IS_PRESENT; >> + if (!pmd_uffd_wp(pmd)) >> + categories |= PAGE_IS_WRITTEN; >> + if (is_zero_pfn(pmd_pfn(pmd))) >> + categories |= PAGE_IS_PFNZERO; >> + } else if (is_swap_pmd(pmd)) { >> + categories |= PAGE_IS_SWAPPED; >> + if (!pmd_swp_uffd_wp(pmd)) >> + categories |= PAGE_IS_WRITTEN; >> + } >> + >> + return categories; >> +} > [...] >> +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >> + >> +#ifdef CONFIG_HUGETLB_PAGE >> +static unsigned long pagemap_hugetlb_category(pte_t pte) >> +{ >> + unsigned long categories = 0; >> + >> + if (pte_present(pte)) { >> + categories |= PAGE_IS_PRESENT; >> + if (!huge_pte_uffd_wp(pte)) >> + categories |= PAGE_IS_WRITTEN; >> + if (!PageAnon(pte_page(pte))) >> + categories |= PAGE_IS_FILE; >> + if (is_zero_pfn(pte_pfn(pte))) >> + categories |= PAGE_IS_PFNZERO; >> + } else if (is_swap_pte(pte)) { >> + categories |= PAGE_IS_SWAPPED; >> + if (!pte_swp_uffd_wp_any(pte)) >> + categories |= PAGE_IS_WRITTEN; >> + } >> + >> + return categories; >> +} > > Could you add PAGE_IS_HUGE for THP and HugeTLB pages? This would help > maintaining checkpointed process'es page sizes by CRIU when THP is > used. Can be done. > > Best Regards > Michał Mirosław -- BR, Muhammad Usama Anjum