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 9F55DEB64DC for ; Wed, 28 Jun 2023 11:09:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3BD088D0005; Wed, 28 Jun 2023 07:09:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 36C748D0001; Wed, 28 Jun 2023 07:09:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 25B2F8D0005; Wed, 28 Jun 2023 07:09:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 162FB8D0001 for ; Wed, 28 Jun 2023 07:09:15 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id B9D691C8D7C for ; Wed, 28 Jun 2023 11:09:14 +0000 (UTC) X-FDA: 80951885028.13.220AD8E Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf06.hostedemail.com (Postfix) with ESMTP id E1A9C180016 for ; Wed, 28 Jun 2023 11:09:12 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687950553; 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; bh=OhSM8ZP9yzxsGiwj6OMKWaTgfjjkrIJ8PohUz6gedRg=; b=3RN+rs1QKkugwnawPvHbbSUGJJcF5Y6wx7tJoemglX2UJXID4lt/qo+eNDBw5qe3wK+UoN j/dpRSSp6yd7yF3/Gzfns80Rbu4QmaEUxpPiWpVkpQF6eTkCCsX9nAdzWdE/EhAtqnlMob fb9kaS1QXKgRIDxqHSFU4x3Jh8k+Hho= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687950553; a=rsa-sha256; cv=none; b=Uh5USdd0dmb2AhkNlACMtJqfG3JGI4kKmtY8tAoBvVy4ofCXYGUI8XfeGWy+swGMBDx2lX +aEc2Zf3AxS5x5NoNRV9/Ntxvows5Iy+QgVAIMjJkwrKCpxw2YvFppHj1rqCnSQqSK4aC+ DiHVpASJ2dRuXS7HJ4XrDrWL45jX370= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9E2D2113E; Wed, 28 Jun 2023 04:09:55 -0700 (PDT) Received: from [10.57.76.180] (unknown [10.57.76.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E67543F663; Wed, 28 Jun 2023 04:09:08 -0700 (PDT) Message-ID: Date: Wed, 28 Jun 2023 12:09:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v1 04/10] mm: Implement folio_add_new_anon_rmap_range() To: Yin Fengwei , Yu Zhao Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , David Hildenbrand , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org References: <20230626171430.3167004-1-ryan.roberts@arm.com> <20230626171430.3167004-5-ryan.roberts@arm.com> <8c01486f-3c1a-e50d-544e-502eadbddf05@intel.com> From: Ryan Roberts In-Reply-To: <8c01486f-3c1a-e50d-544e-502eadbddf05@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: E1A9C180016 X-Rspam-User: X-Stat-Signature: hkssptmo5pc9755qj7x99nuhm97kjnoy X-Rspamd-Server: rspam03 X-HE-Tag: 1687950552-725844 X-HE-Meta: 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 W5Bg6TfH 9IdQWBmB8ScrLp9csPs9iOLRUigsejo2rT4xL8zA8Pzuzgk0VbvWCuCGCIwEeonIxKwC/y3Q+qYOPIzhZtdsiw+ALJG32qBKZ4e9CGn+oV36e0Z7hzj5V4AWmRGTx6Ex6oiPSbyU3WAdjOR8jwKDczmehg7UnJpqLPKiZ2Mr7yuwJj84yFHBJlHZJrl1Awvo2mJWm3abh0/gOYdEE33N3EUABCAM+OXlEH3hzkjPfI+BAeDa637PhH/YFfqI197hykORfkZ10Jl2XIOxXvjNsF6S0gmhU6VP8pmS760ATrYzRppTyBAnNqDZ8KZugO5OvWDF16uebxnk0d4WHVLxA2sZ3+g== 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 28/06/2023 03:20, Yin Fengwei wrote: > > > On 6/27/23 16:09, Ryan Roberts wrote: >> On 27/06/2023 08:08, Yu Zhao wrote: >>> On Mon, Jun 26, 2023 at 11:14 AM Ryan Roberts wrote: >>>> >>>> Like folio_add_new_anon_rmap() but batch-rmaps a range of pages >>>> belonging to a folio, for effciency savings. All pages are accounted as >>>> small pages. >>>> >>>> Signed-off-by: Ryan Roberts >>>> --- >>>> include/linux/rmap.h | 2 ++ >>>> mm/rmap.c | 43 +++++++++++++++++++++++++++++++++++++++++++ >>>> 2 files changed, 45 insertions(+) >>>> >>>> diff --git a/include/linux/rmap.h b/include/linux/rmap.h >>>> index a3825ce81102..15433a3d0cbf 100644 >>>> --- a/include/linux/rmap.h >>>> +++ b/include/linux/rmap.h >>>> @@ -196,6 +196,8 @@ void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, >>>> unsigned long address); >>>> void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *, >>>> unsigned long address); >>>> +void folio_add_new_anon_rmap_range(struct folio *folio, struct page *page, >>>> + int nr, struct vm_area_struct *vma, unsigned long address); >>> >>> We should update folio_add_new_anon_rmap() to support large() && >>> !folio_test_pmd_mappable() folios instead. >>> >>> I double checked all places currently using folio_add_new_anon_rmap(), >>> and as expected, none actually allocates large() && >>> !folio_test_pmd_mappable() and maps it one by one, which makes the >>> cases simpler, i.e., >>> if (!large()) >>> // the existing basepage case >>> else if (!folio_test_pmd_mappable()) >>> // our new case >>> else >>> // the existing THP case >> >> I don't have a strong opinion either way. Happy to go with this suggestion. But >> the reason I did it as a new function was because I was following the pattern in >> [1] which adds a new folio_add_file_rmap_range() function. >> >> [1] https://lore.kernel.org/linux-mm/20230315051444.3229621-35-willy@infradead.org/ > Oh. There is different here: > For page cache, large folio could be created by previous file access. But later > file access by other process just need map partial large folio. In this case, we need > _range for filemap. > > But for anonymous, I suppose we always map whole folio in. So I agree with Yu. We > don't need _range for folio_add_new_anon_rmap(). Thanks. Yes that makes sense - thanks. I'll merge the new case into folio_add_new_anon_rmap() for v2. > > > Regards > Yin, Fengwei > >> >> >>> >>>> void page_add_file_rmap(struct page *, struct vm_area_struct *, >>>> bool compound); >>>> void folio_add_file_rmap_range(struct folio *, struct page *, unsigned int nr, >>>> diff --git a/mm/rmap.c b/mm/rmap.c >>>> index 1d8369549424..4050bcea7ae7 100644 >>>> --- a/mm/rmap.c >>>> +++ b/mm/rmap.c >>>> @@ -1305,6 +1305,49 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, >>>> __page_set_anon_rmap(folio, &folio->page, vma, address, 1); >>>> } >>>> >>>> +/** >>>> + * folio_add_new_anon_rmap_range - Add mapping to a set of pages within a new >>>> + * anonymous potentially large folio. >>>> + * @folio: The folio containing the pages to be mapped >>>> + * @page: First page in the folio to be mapped >>>> + * @nr: Number of pages to be mapped >>>> + * @vma: the vm area in which the mapping is added >>>> + * @address: the user virtual address of the first page to be mapped >>>> + * >>>> + * Like folio_add_new_anon_rmap() but batch-maps a range of pages within a folio >>>> + * using non-THP accounting. Like folio_add_new_anon_rmap(), the inc-and-test is >>>> + * bypassed and the folio does not have to be locked. All pages in the folio are >>>> + * individually accounted. >>>> + * >>>> + * As the folio is new, it's assumed to be mapped exclusively by a single >>>> + * process. >>>> + */ >>>> +void folio_add_new_anon_rmap_range(struct folio *folio, struct page *page, >>>> + int nr, struct vm_area_struct *vma, unsigned long address) >>>> +{ >>>> + int i; >>>> + >>>> + VM_BUG_ON_VMA(address < vma->vm_start || >>>> + address + (nr << PAGE_SHIFT) > vma->vm_end, vma); >>> >>> BTW, VM_BUG_ON* shouldn't be used in new code: >>> Documentation/process/coding-style.rst >> >> Thanks, sorry about that. Was copy-pasting from folio_add_new_anon_rmap(). >>