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 9C392C3A5A7 for ; Tue, 6 Dec 2022 09:16:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BCDBE8E0002; Tue, 6 Dec 2022 04:16:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B7D288E0001; Tue, 6 Dec 2022 04:16:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A45A08E0002; Tue, 6 Dec 2022 04:16:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 9443B8E0001 for ; Tue, 6 Dec 2022 04:16:21 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 44DE41A0CA0 for ; Tue, 6 Dec 2022 09:16:21 +0000 (UTC) X-FDA: 80211325362.07.DB61795 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf18.hostedemail.com (Postfix) with ESMTP id CE06C1C000D for ; Tue, 6 Dec 2022 09:16:20 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="JNU/WMEn"; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1670318180; 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=lMRy72lNTyTvf37gL8dnH7NCNPDUhgTIYeO671gopCE=; b=ATAVoGyM63bcL9Rb4YBNcUHbD2tBZr8kyI6G77+cxWF45JF5RwQeEyaNygzqNK/OYr3BJu /76+0mKZtddoW1HkRrAlyeQ3x5+mHdPjzOZARS71FcfTQBE9gpXYJT7/+zQ2zsvOEIcDsf S5QSmKqZ4IXI5kHPm9++9luf2eZJ+yo= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="JNU/WMEn"; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1670318180; a=rsa-sha256; cv=none; b=kTCpqEYr9/6uuqXJh+nYt/Flg7byeLZjtgOVQ8NErLCvBrNPs4d/XTDa8xpkA+5GO28BtE nWyEeit/b/8FSU7qyv95mpXdKGYwidLy4w7w3phla45uprfb4+bSyqS5lmESNoxXWXgp0z 0Dknd0PAsI4DDE/smGuVV59Sit/LftY= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670318180; h=from:from: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=lMRy72lNTyTvf37gL8dnH7NCNPDUhgTIYeO671gopCE=; b=JNU/WMEnH0zioLo66aPA6mZCEcY2zVNoC4rPJRnEqgP0ZnzuRf6PN6zEdRnQHoJ1Ouse0E /2+fxvvG8f47I+LnnaAYuNF5MCAzY/CqKNGRqTry17/xsLkUMpPMm2+2b3CvO8es70DpRB USkROK3WMK1L2VimtatqJO71Z+eA2sU= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-212-ZgUS4YM6MfyJLN83PYHShQ-1; Tue, 06 Dec 2022 04:16:11 -0500 X-MC-Unique: ZgUS4YM6MfyJLN83PYHShQ-1 Received: by mail-wr1-f70.google.com with SMTP id o8-20020adfba08000000b00241e80f08e0so3011947wrg.12 for ; Tue, 06 Dec 2022 01:16:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:subject:organization:from :references:cc:to:content-language:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=lMRy72lNTyTvf37gL8dnH7NCNPDUhgTIYeO671gopCE=; b=fkPVe08/MOJ43RYHiGEG/MZLY5T/6aI7D96Kb0MPNc5wVL1wgoOHx/I0OpCjwwBk1w m8RZrosinwwx77uiYH1yIpWtYf3Mdk4wFQNVzX/SAW+EFm/ELeIr+nJ1LT1GNzGjJv+g VuRvTCXoVCQoy98jkjuOd2F6E/Y9qIPOFjMneWM0I7aChbJ56lgy3jzdtuwQ3XlBuGtg 7LKvJNfc9eA0b/pB2Naz9Pe/R0Kv1dk1sBT2ECh8YUpUHcvR9fuEyzvJ7HbtgebPbrkY f7Z5TPhA0ZKN+IcoAw4rY7Ep3bMOdfiUUhpov8hnw79/h6TNokz20PntPbmDdlicVrPP TmHg== X-Gm-Message-State: ANoB5plhKDC5Mnl0HTIJyBeoeNdSIMY693YnR3jzOE6bOhX0Ks+iqZXF VNXRN1cbaqN35zNqv/N6+pVlRwHsT+1br6spSdk0ZNzVo/rZvYY3tEx/nsN6BjizXnCEC80o1YX 4PhhPnt0cfa4= X-Received: by 2002:a05:6000:192:b0:242:4d66:d10 with SMTP id p18-20020a056000019200b002424d660d10mr7898450wrx.504.1670318170283; Tue, 06 Dec 2022 01:16:10 -0800 (PST) X-Google-Smtp-Source: AA0mqf6lMBFp4LDO+TjiQzgMfKj1b8zuPe3WXQz7UTJO1PSntr02Vc7xM+ehsJ+ySDXUAffMfkhIbw== X-Received: by 2002:a05:6000:192:b0:242:4d66:d10 with SMTP id p18-20020a056000019200b002424d660d10mr7898430wrx.504.1670318169962; Tue, 06 Dec 2022 01:16:09 -0800 (PST) Received: from ?IPV6:2003:cb:c705:4f00:41f1:185d:4f9f:d1c2? (p200300cbc7054f0041f1185d4f9fd1c2.dip0.t-ipconnect.de. [2003:cb:c705:4f00:41f1:185d:4f9f:d1c2]) by smtp.gmail.com with ESMTPSA id i12-20020adffc0c000000b00241d21d4652sm16031066wrr.21.2022.12.06.01.16.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 06 Dec 2022 01:16:09 -0800 (PST) Message-ID: <0b122e73-22c3-e3a3-3aaf-d2b8361c196d@redhat.com> Date: Tue, 6 Dec 2022 10:16:08 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 To: Peter Xu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Yang Shi , Hugh Dickins , Andrea Arcangeli References: <20221205150857.167583-1-david@redhat.com> From: David Hildenbrand Organization: Red Hat Subject: Re: [PATCH v1] mm/swap: fix SWP_PFN_BITS with CONFIG_PHYS_ADDR_T_64BIT on 32bit In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spamd-Result: default: False [-1.90 / 9.00]; BAYES_HAM(-6.00)[100.00%]; SORBS_IRL_BL(3.00)[209.85.221.70:received]; SUBJECT_HAS_UNDERSCORES(1.00)[]; MIME_GOOD(-0.10)[text/plain]; RCVD_NO_TLS_LAST(0.10)[]; BAD_REP_POLICIES(0.10)[]; R_SPF_ALLOW(0.00)[+ip4:170.10.133.0/24]; RCPT_COUNT_SEVEN(0.00)[7]; DMARC_POLICY_ALLOW(0.00)[redhat.com,none]; DKIM_TRACE(0.00)[redhat.com:+]; R_DKIM_ALLOW(0.00)[redhat.com:s=mimecast20190719]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; HAS_ORG_HEADER(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; PREVIOUSLY_DELIVERED(0.00)[linux-mm@kvack.org]; MID_RHS_MATCH_FROM(0.00)[]; ARC_SIGNED(0.00)[hostedemail.com:s=arc-20220608:i=1]; RCVD_VIA_SMTP_AUTH(0.00)[] X-Rspamd-Queue-Id: CE06C1C000D X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 1p9eosj4o9zr9nsxcmzewbxydpmhfz7h X-HE-Tag: 1670318180-893714 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: > > Thanks for debugging this one. Sure! > >> --- >> >> This makes my x86 PAE case work as expected again. Only cross compiled >> on other architectures. > > IIUC it's not about PAE but !SPARSEMEM, as PAE actually has it defined when > with sparsemem: > > #ifdef CONFIG_X86_32 > # ifdef CONFIG_X86_PAE > # define SECTION_SIZE_BITS 29 > # define MAX_PHYSMEM_BITS 36 > # else > # define SECTION_SIZE_BITS 26 > # define MAX_PHYSMEM_BITS 32 > # endif > #else /* CONFIG_X86_32 */ > # define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */ > # define MAX_PHYSMEM_BITS (pgtable_l5_enabled() ? 52 : 46) > #endif Indeed, I'll extend the description accordingly. > > One trivial comment below. > >> >> --- >> include/linux/swapops.h | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/swapops.h b/include/linux/swapops.h >> index 86b95ccb81bb..4bb7a20f3fa5 100644 >> --- a/include/linux/swapops.h >> +++ b/include/linux/swapops.h >> @@ -32,11 +32,13 @@ >> * store PFN, we only need SWP_PFN_BITS bits. Each of the pfn swap entries >> * can use the extra bits to store other information besides PFN. >> */ >> -#ifdef MAX_PHYSMEM_BITS >> +#if defined(MAX_PHYSMEM_BITS) >> #define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) >> -#else /* MAX_PHYSMEM_BITS */ >> +#elif !defined(CONFIG_64BIT) && defined(CONFIG_PHYS_ADDR_T_64BIT) >> +#define SWP_PFN_BITS SWP_TYPE_SHIFT > > Can we add a comment showing where SWP_TYPE_SHIFT comes from? It should be > a min value comes from either the limitation of phys address width, or from > definition of swp_entry_t (which is unsigned long). > > Or I'd rather make this then the code explains better on itself, and the > change should be smaller too: > > #ifdef MAX_PHYSMEM_BITS > #define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) > #else /* MAX_PHYSMEM_BITS */ > -#define SWP_PFN_BITS (BITS_PER_LONG - PAGE_SHIFT) > +#define SWP_PFN_BITS MIN((sizeof(phys_addr_t) * 8) - \ > + PAGE_SHIFT, SWP_TYPE_SHIFT) > #endif /* MAX_PHYSMEM_BITS */ > #define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) > > What do you think? Sure, if we can make the compiler happy: ./include/linux/swapops.h: In function 'swp_offset_pfn': ./include/linux/swapops.h:38:41: error: implicit declaration of function 'MIN' [-Werror=implicit-function-declaration] 38 | #define SWP_PFN_BITS MIN((sizeof(phys_addr_t) * 8) - \ | ^~~ ./include/vdso/bits.h:7:44: note: in definition of macro 'BIT' 7 | #define BIT(nr) (UL(1) << (nr)) | ^~ ./include/linux/swapops.h:41:46: note: in expansion of macro 'SWP_PFN_BITS' 41 | #define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) | ^~~~~~~~~~~~ ./include/linux/swapops.h:119:36: note: in expansion of macro 'SWP_PFN_MASK' 119 | return swp_offset(entry) & SWP_PFN_MASK; | ^~~~~~~~~~~~ using "min" instead gives plenty of warnings. min_t() seems to work: diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 27ade4f22abb..088f25aa0e98 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -34,8 +34,10 @@ */ #ifdef MAX_PHYSMEM_BITS #define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) -#else /* MAX_PHYSMEM_BITS */ -#define SWP_PFN_BITS (BITS_PER_LONG - PAGE_SHIFT) +#else /* MAX_PHYSMEM_BITS */ +#define SWP_PFN_BITS min_t(phys_addr_t, \ + (sizeof(phys_addr_t) * 8) - \ + PAGE_SHIFT, SWP_TYPE_SHIFT) #endif /* MAX_PHYSMEM_BITS */ #define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) I'm currently cross-compiling that and will give it a churn. Thanks! -- Thanks, David / dhildenb