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 ACA29E71D3F for ; Fri, 29 Sep 2023 14:39:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2D59C8D00D5; Fri, 29 Sep 2023 10:39:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 286618D0023; Fri, 29 Sep 2023 10:39:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 174A38D00D5; Fri, 29 Sep 2023 10:39:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 07A688D0023 for ; Fri, 29 Sep 2023 10:39:56 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C6F74C04A1 for ; Fri, 29 Sep 2023 14:39:55 +0000 (UTC) X-FDA: 81289894350.03.F7DDDBC Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf10.hostedemail.com (Postfix) with ESMTP id 90F7BC0011 for ; Fri, 29 Sep 2023 14:39:53 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf10.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695998394; 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=uNqranZXziD//UJBRCCiwV5+pJ8TfgfqhYrdGwhSLh4=; b=aLD1v7nfoX2CCHuNTt6iDE+2Ga6YHd+xnEc5O2DhGTdxs3hcK+an/4tXiwD79l2eKIoH+n Fbknyk7RtYzv4AsuZn0sZiqjbPFpxNIrRWWXN71vG16oaDitekY3iw5irUwojUk4h00T0A rOQHob2n1Jd8ZuCbUMsv9uUMhDagJPY= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf10.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695998394; a=rsa-sha256; cv=none; b=WnDvfBjHCscskpc4rqCagEY4qdUWCfvn/pZU3krFjEFUFJWR9SUD9AOfNaAkwYOO7Heb5D mhxi+3/wrcTiPODTlCzeG7hYKX7GM0GbCUjnsTW9QbKPvU9eRRyFuh1cifaCRRmCfvsH24 nSLVS3w1PMb/Z9gyI244jDXrZ7yzVqs= 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 C7A631FB; Fri, 29 Sep 2023 07:40:30 -0700 (PDT) Received: from [10.57.66.194] (unknown [10.57.66.194]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DD23F3F5A1; Fri, 29 Sep 2023 07:39:49 -0700 (PDT) Message-ID: <188646a6-c854-4fbe-96ff-ddf3ffc5ec77@arm.com> Date: Fri, 29 Sep 2023 15:39:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/9] mm: Non-pmd-mappable, large folios for folio_add_new_anon_rmap() Content-Language: en-GB To: "Kirill A. Shutemov" Cc: Andrew Morton , Matthew Wilcox , Yin Fengwei , David Hildenbrand , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , John Hubbard , David Rientjes , Vlastimil Babka , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20230929114421.3761121-1-ryan.roberts@arm.com> <20230929114421.3761121-3-ryan.roberts@arm.com> <20230929134524.wwyykrxfikhle54k@box.shutemov.name> From: Ryan Roberts In-Reply-To: <20230929134524.wwyykrxfikhle54k@box.shutemov.name> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 90F7BC0011 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: f1zufe9gkg9cwsdy9wmf4tfpnzpnwoyw X-HE-Tag: 1695998393-912115 X-HE-Meta: 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 2ospPQTb w+Ryr4HlYovAwuecLSnuzAUPxLGbqqW5nxd4st0hUdWL9S04XmgLDlpfF6O2aRl+xXKxzILnKdSIGJylJKdEgMCt+Iy/CYyBXiUs7dkSojHRsXUXHG+nwN4QvSIbuH8eIJ9vbXjCPfRoEoNT+TyKUSMAGiEYiczmwqprV1EaTlw9DVP2AMK3GfYstRBxatJK9f3/a4I4WaWfui8W3S27qxtyVVL5I6eApkItAxGDim4KmU4kM4AzPX3E0iyPMZpZCCIqWbPJGCw2bac0bG3WL320KNUlu6p5knpdaAWTXDa8ZM2b4u2PNS2zNT0VMIybCIOhTc8YVP2ArkWgMOqDZqHAXf7XavMxywcqc8C7+3Zy9JKAyiKgWVg1BdQ== 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 29/09/2023 14:45, Kirill A. Shutemov wrote: > On Fri, Sep 29, 2023 at 12:44:13PM +0100, Ryan Roberts wrote: >> In preparation for anonymous large folio support, improve >> folio_add_new_anon_rmap() to allow a non-pmd-mappable, large folio to be >> passed to it. In this case, all contained pages are accounted using the >> order-0 folio (or base page) scheme. >> >> Reviewed-by: Yu Zhao >> Reviewed-by: Yin Fengwei >> Signed-off-by: Ryan Roberts >> --- >> mm/rmap.c | 27 ++++++++++++++++++++------- >> 1 file changed, 20 insertions(+), 7 deletions(-) >> >> diff --git a/mm/rmap.c b/mm/rmap.c >> index 8600bd029acf..106149690366 100644 >> --- a/mm/rmap.c >> +++ b/mm/rmap.c >> @@ -1266,31 +1266,44 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, >> * This means the inc-and-test can be bypassed. >> * The folio does not have to be locked. >> * >> - * If the folio is large, it is accounted as a THP. As the folio >> + * If the folio is pmd-mappable, it is accounted as a THP. As the folio >> * is new, it's assumed to be mapped exclusively by a single process. >> */ >> void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, >> unsigned long address) >> { >> - int nr; >> + int nr = folio_nr_pages(folio); >> >> - VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); >> + VM_BUG_ON_VMA(address < vma->vm_start || >> + address + (nr << PAGE_SHIFT) > vma->vm_end, vma); >> __folio_set_swapbacked(folio); >> >> - if (likely(!folio_test_pmd_mappable(folio))) { >> + if (likely(!folio_test_large(folio))) { >> /* increment count (starts at -1) */ >> atomic_set(&folio->_mapcount, 0); >> - nr = 1; >> + __page_set_anon_rmap(folio, &folio->page, vma, address, 1); >> + } else if (!folio_test_pmd_mappable(folio)) { >> + int i; >> + >> + for (i = 0; i < nr; i++) { >> + struct page *page = folio_page(folio, i); >> + >> + /* increment count (starts at -1) */ >> + atomic_set(&page->_mapcount, 0); >> + __page_set_anon_rmap(folio, page, vma, >> + address + (i << PAGE_SHIFT), 1); >> + } >> + >> + atomic_set(&folio->_nr_pages_mapped, nr); > > This code should work for !folio_test_large() case too, no? Not quite; for !folio_test_large() we don't set _nr_pages_mapped - that's a compound-only field in the second struct page. So I could make most of this common but would still have a conditional around that last line, and at that point I thought it was better to split it the way I've done it to avoid the loop overhead for the !large case. > >> } else { >> /* increment count (starts at -1) */ >> atomic_set(&folio->_entire_mapcount, 0); >> atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED); >> - nr = folio_nr_pages(folio); >> + __page_set_anon_rmap(folio, &folio->page, vma, address, 1); >> __lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr); >> } >> >> __lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr); >> - __page_set_anon_rmap(folio, &folio->page, vma, address, 1); >> } >> >> /** >> -- >> 2.25.1 >> >