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 1783FC27C76 for ; Thu, 26 Jan 2023 00:28:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 911C86B0071; Wed, 25 Jan 2023 19:28:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C1D76B0072; Wed, 25 Jan 2023 19:28:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7897F6B0073; Wed, 25 Jan 2023 19:28:18 -0500 (EST) 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 6475D6B0071 for ; Wed, 25 Jan 2023 19:28:18 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 36EB51C6618 for ; Thu, 26 Jan 2023 00:28:18 +0000 (UTC) X-FDA: 80395063476.29.92ED7D5 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf21.hostedemail.com (Postfix) with ESMTP id 6AE8F1C000B for ; Thu, 26 Jan 2023 00:28:16 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=KuBUX56v; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 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=1674692896; 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=M5XdLuNoIKhfhvMYBVOvUO5yAnd2aWDhjlTCUQ/4Udw=; b=ZSz9ShKyC9+XX6L86qd+5ar18mQPOSmY2VHYtsRcj9pqTal/jbajPBzB+uKMuryAI9FtaW PAVvwWQbzUL608M/Zir2PYUfWSPHzNdpMlSSCsJBySdKjvZ406CJEz4ezziPsuuOPdQ1qk LcCxD0lqyI5V97qBF+buJwpUxJxc8/s= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=KuBUX56v; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674692896; a=rsa-sha256; cv=none; b=69mXW1W8TW+thUOPOcVdNXSPUgH4duqmlIJ+bS9o0IdTNmcJeGKJFiopR484s7urWuxCgQ jjKxLPoBf4EZO3pBGZMxzCdEnK9AUKTUSp3XLzCzjtuMLaQ4DtFJgpiTtVqDN0dTQLKueE mc6i4zHNSdqtFeZMpyQcQbYLyYjR4no= Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A582FB81BA0; Thu, 26 Jan 2023 00:28:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9EDCC433EF; Thu, 26 Jan 2023 00:28:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1674692893; bh=Rts4+1Au/Ll1O1kl9uisvJrfAICueoMmMPvZ7zzpAqw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=KuBUX56vtogE4UJe6QcxCQYV1fnGIIAVDRHmEfVf7Io28I7Qne+FMKR+WO3/aPVQ9 +q9b0nfdwqAjtDr4j+Krm5O7RMTO6yhEukGdW/S9RprylHXNKdIq2CXUQIL16AJEf+ a+rdH26novPowhDFg08/Fuj5XWuEI0u+LyTNj48k= Date: Wed, 25 Jan 2023 16:28:10 -0800 From: Andrew Morton To: Suren Baghdasaryan Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3 2/7] mm: introduce vma->vm_flags wrapper functions Message-Id: <20230125162810.ec222773d13cd26c55991fde@linux-foundation.org> In-Reply-To: <20230125233554.153109-3-surenb@google.com> References: <20230125233554.153109-1-surenb@google.com> <20230125233554.153109-3-surenb@google.com> X-Mailer: Sylpheed 3.7.0 (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-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 6AE8F1C000B X-Rspam-User: X-Stat-Signature: moqx1zmc166wsc9scnftwwihn9xszpoy X-HE-Tag: 1674692896-185250 X-HE-Meta: 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 OuS5ptWj 4PDe2n8nyC0CBKMZ0/dOHOPZCyWr7gta6yRHVN8RIVHpLTzgbhH0xocTJ/ppAIrtPBD/PT0EdxOwHuWMWOp0NAWpTiQrC+I3CoERuVVbUvtJOEVh0plKwOK9/l4nb2TN/NyQF7wYMawmgiaDN6QND8QNT/xGN7TTv+11mP3owl5oGIw+ZMezBQKiGe28e8JQc/uGU3ZgogvdEBeB4ZRCDaKb09ILUPdsg3auVxW+f3bkSz53S/cAU6qSghqbiTbLygohuORLAnhirmiay8zdgI9RdAIKu6gwFFC/MUyBU7C0H39Y69sCJRUrdedNjRSqcvcBy9fKeMzolMZUvN13QImDIGz4jOGsYH6n0Q5lHwg/axLomMeD68aXTKZmsePKyVA4pRgXBm9BYY9f0OVlYoLE5zenn5L0dC0+8 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 Wed, 25 Jan 2023 15:35:49 -0800 Suren Baghdasaryan wrote: > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -491,7 +491,15 @@ struct vm_area_struct { > * See vmf_insert_mixed_prot() for discussion. > */ > pgprot_t vm_page_prot; > - unsigned long vm_flags; /* Flags, see mm.h. */ > + > + /* > + * Flags, see mm.h. > + * To modify use {init|reset|set|clear|mod}_vm_flags() functions. > + */ > + union { > + const vm_flags_t vm_flags; > + vm_flags_t __private __vm_flags; > + }; Typically when making a change like this we'll rename the affected field/variable/function/etc. This will reliably and deliberately break unconverted usage sites. This const trick will get us partway there, by breaking setters. But renaming it will break both setters and getters.