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 8D8E3EE4990 for ; Tue, 30 Dec 2025 18:10:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 751346B0088; Tue, 30 Dec 2025 13:10:33 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6FF586B0089; Tue, 30 Dec 2025 13:10:33 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 60C396B008A; Tue, 30 Dec 2025 13:10:33 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 4E5566B0088 for ; Tue, 30 Dec 2025 13:10:33 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id D435413A7D9 for ; Tue, 30 Dec 2025 18:10:32 +0000 (UTC) X-FDA: 84276927504.19.9F5E486 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf08.hostedemail.com (Postfix) with ESMTP id 27D8A16000A for ; Tue, 30 Dec 2025 18:10:31 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=fdEij2TB; spf=pass (imf08.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767118231; 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=/JuR8HE8mfPa9jY7HutISL8z4nsVzug8C0Lgd99O3D8=; b=E4nJ5fd+psL/O31pj/gzO1FJkr3n2WRANSyYBkewUSAtWfDpV7Cw02k5lnVWi0YzLD9UYx 5fUb2wrfDd15XSwx/AQlJV46dwRGzTF3btbyIFkSQ/o9aqqLJDsTmhoBcfJWxBnAh9/se2 qVD0X/ibUOnqkCyYTc+prba+QELtWL4= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=fdEij2TB; spf=pass (imf08.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1767118231; a=rsa-sha256; cv=none; b=aY4LdbJQHvExg1F6pysvPogy1XpIAvtUNSZmjjkDz0YHQDuQ63clh/9VzxqG122MgAPWlv niBStdWfBKlCdogzgIZk9eEKHuAq/NP9OrZJH7AMrMhlbm/XXpKT6ZRFrUOs5egf7OzNzQ CxwBhLZndzZp7IZ1sEJ5isvni9Vchx4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 2EBA460017; Tue, 30 Dec 2025 18:10:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9ACF3C4CEFB; Tue, 30 Dec 2025 18:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1767118229; bh=syp7Zgtx+zgJ1L0ASo6OlDm55/XqkgxP5b6kmNbRhvA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fdEij2TBe/dyl21797aoUsSaASOQmLEgBanqAD7lue1GY0UUa4e7oes1/jVke3FdK Q2evTpkMKMWw3DLcx3WE69kGa32lNeKsbxsNlILIJVECR7gD4D0mz7ywP2nEG5jAIl PDfIHV/ZYQE7pHt8DS2fV7RwIN/QsfD8zKFK8Fhg= Date: Tue, 30 Dec 2025 10:10:29 -0800 From: Andrew Morton To: Wale Zhang Cc: chrisl@kernel.org, ziy@nvidia.com, lorenzo.stoakes@oracle.com, david@kernel.org, baohua@kernel.org, matthew.brost@intel.com, linux-mm@kvack.org Subject: Re: [PATCH v2] mm/swapops,rmap: remove should-never-be-compiled codes. Message-Id: <20251230101029.8471aea6c786ab33a85c55ca@linux-foundation.org> In-Reply-To: <20251230130110.1366374-1-wale.zhang.ftd@gmail.com> References: <20251230130110.1366374-1-wale.zhang.ftd@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: tnm9gny8krxrw8p8m9op8uqq55xkhxu7 X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 27D8A16000A X-HE-Tag: 1767118231-863293 X-HE-Meta: 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 5IyZdad2 LR7q60p7H7phunvDnv1kGTtpiBmyt3cJp1YjclR2mfbjWIaJ+nFvG8Gug/HSz3BYHbRIXznk/9eb5XUgWJoNrbtrhgQZn67V9Vm+O+SC1KJkpXS5q3Dx4a0nsiKTBkPj9JQSvp4pf52XpRp4wWIDmMH83pI930pH48bQNczg3BDC2CaI96Dq6uruuiOlDMcfTOYmRV6gJbqAecc+ufknSkGiWfmmos6OBXHNtpp6MWcoaTzUwUhmd6LZx6/RpJ9y9KMlet5BnmWvsDObgY8Q9aE+Lijg3FJTPfeHvK0NabOPnHUVqikmWEQjjTdIzzf9rQwrF/o3hIEfPkujY4kcE3XE0+Q== 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: List-Subscribe: List-Unsubscribe: On Tue, 30 Dec 2025 21:01:10 +0800 Wale Zhang wrote: > mm/swapops,rmap: remove should-never-be-compiled codes, included > folio_add_return_large_mapcount(), folio_sub_return_large_mapcount(), > set_pmd_migration_entry() and remove_migration_pmd(). Please provide a reason for making this change. > > ... > > @@ -1264,22 +1262,21 @@ static __always_inline void __folio_add_rmap(struct folio *folio, > nr = first; > > folio_add_large_mapcount(folio, orig_nr_pages, vma); > +#endif > break; > case PGTABLE_LEVEL_PMD: > case PGTABLE_LEVEL_PUD: > first = atomic_inc_and_test(&folio->_entire_mapcount); > - if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT)) { > - if (level == PGTABLE_LEVEL_PMD && first) > - nr_pmdmapped = folio_large_nr_pages(folio); > - nr = folio_inc_return_large_mapcount(folio, vma); > - if (nr == 1) > - /* Was completely unmapped. */ > - nr = folio_large_nr_pages(folio); > - else > - nr = 0; > - break; > - } > - > +#ifdef CONFIG_NO_PAGE_MAPCOUNT > + if (level == PGTABLE_LEVEL_PMD && first) > + nr_pmdmapped = folio_large_nr_pages(folio); > + nr = folio_inc_return_large_mapcount(folio, vma); > + if (nr == 1) > + /* Was completely unmapped. */ > + nr = folio_large_nr_pages(folio); > + else > + nr = 0; > +#else Changes like this made the code unpleasant to read and harder to work on. What do we get in return for this?