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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40902C433DB for ; Fri, 26 Feb 2021 15:59:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A110664F03 for ; Fri, 26 Feb 2021 15:59:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A110664F03 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 220786B0005; Fri, 26 Feb 2021 10:59:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A8896B0006; Fri, 26 Feb 2021 10:59:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 071F86B006C; Fri, 26 Feb 2021 10:59:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id E10CC6B0005 for ; Fri, 26 Feb 2021 10:59:29 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id A6AC6180AD82F for ; Fri, 26 Feb 2021 15:59:29 +0000 (UTC) X-FDA: 77860878858.26.6F232F0 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id 7A180E00011E for ; Fri, 26 Feb 2021 15:59:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=LBaKHm661e2/pCw2/WvK+r7G9CV6irEmIaQaUTUrM/I=; b=sW/OjqIpj6duvHj3cvoK44nFoC Bbj/3yA8GY9h9BMJAKOOsa5sW+pBKuHPgCK5xKV5CxRPmDmphYR8ev591rOD/YKAznDD1X97olu6c JqboHG2zspmXFBui0uTbvpSPO3gWFX/hBaAd3ovQ/+mnW7ZYkfHh6Yzw3clipK+bmYjnenJBrNncl EVwfdz5giJvu80Ps9BWVccGfx72XsL1x7uaKseu4ViUxtPcy92u9OLoA8RiBo1yzcbbiZES8i4h+w rkil1V1rVJNY20RGNZhZ2F9vLWiPqyCS7yIrh4N+HToimxqsr/RB254l0GAlWbiSjJ2eTpKg8QpRR xL62pMxg==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lFfWH-00CD0S-J5; Fri, 26 Feb 2021 15:59:11 +0000 Date: Fri, 26 Feb 2021 15:59:09 +0000 From: Christoph Hellwig To: Alistair Popple Cc: linux-mm@kvack.org, nouveau@lists.freedesktop.org, bskeggs@redhat.com, akpm@linux-foundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, jhubbard@nvidia.com, rcampbell@nvidia.com, jglisse@redhat.com, jgg@nvidia.com, hch@infradead.org, daniel@ffwll.ch Subject: Re: [PATCH v3 1/8] mm: Remove special swap entry functions Message-ID: <20210226155909.GA2907711@infradead.org> References: <20210226071832.31547-1-apopple@nvidia.com> <20210226071832.31547-2-apopple@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210226071832.31547-2-apopple@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: n9g7rr5ej8qxuqpo11h3s7sxr91rk9nn X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 7A180E00011E Received-SPF: none (casper.srs.infradead.org>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614355162-231476 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: > - struct page *page = migration_entry_to_page(entry); > + struct page *page = pfn_to_page(swp_offset(entry)); I wonder if keeping a single special_entry_to_page() helper would still me a useful. But I'm not entirely sure. There are also two more open coded copies of this in the THP migration code. > -#define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) > -#define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) > +#define free_swap_and_cache(e) is_special_entry(e) > +#define swapcache_prepare(e) is_special_entry(e) Staring at this I'm really, really confused at what this is doing. Looking a little closer these are the !CONFIG_SWAP stubs, but it could probably use a comment or two. > } else if (is_migration_entry(entry)) { > - page = migration_entry_to_page(entry); > + page = pfn_to_page(swp_offset(entry)); > > rss[mm_counter(page)]++; > > @@ -737,7 +737,7 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, > set_pte_at(src_mm, addr, src_pte, pte); > } > } else if (is_device_private_entry(entry)) { > - page = device_private_entry_to_page(entry); > + page = pfn_to_page(swp_offset(entry)); > > /* > * Update rss count even for unaddressable pages, as > @@ -1274,7 +1274,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, > > entry = pte_to_swp_entry(ptent); > if (is_device_private_entry(entry)) { > - struct page *page = device_private_entry_to_page(entry); > + struct page *page = pfn_to_page(swp_offset(entry)); > > if (unlikely(details && details->check_mapping)) { > /* > @@ -1303,7 +1303,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, > else if (is_migration_entry(entry)) { > struct page *page; > > - page = migration_entry_to_page(entry); > + page = pfn_to_page(swp_offset(entry)); > rss[mm_counter(page)]--; > } > if (unlikely(!free_swap_and_cache(entry))) > @@ -3271,7 +3271,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > migration_entry_wait(vma->vm_mm, vmf->pmd, > vmf->address); > } else if (is_device_private_entry(entry)) { > - vmf->page = device_private_entry_to_page(entry); > + vmf->page = pfn_to_page(swp_offset(entry)); > ret = vmf->page->pgmap->ops->migrate_to_ram(vmf); > } else if (is_hwpoison_entry(entry)) { > ret = VM_FAULT_HWPOISON; > diff --git a/mm/migrate.c b/mm/migrate.c > index 20ca887ea769..72adcc3d8f5b 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -321,7 +321,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > if (!is_migration_entry(entry)) > goto out; > > - page = migration_entry_to_page(entry); > + page = pfn_to_page(swp_offset(entry)); > > /* > * Once page cache replacement of page migration started, page_count > @@ -361,7 +361,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) > ptl = pmd_lock(mm, pmd); > if (!is_pmd_migration_entry(*pmd)) > goto unlock; > - page = migration_entry_to_page(pmd_to_swp_entry(*pmd)); > + page = pfn_to_page(swp_offset(pmd_to_swp_entry(*pmd))); > if (!get_page_unless_zero(page)) > goto unlock; > spin_unlock(ptl); > @@ -2437,7 +2437,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > if (!is_device_private_entry(entry)) > goto next; > > - page = device_private_entry_to_page(entry); > + page = pfn_to_page(swp_offset(entry)); > if (!(migrate->flags & > MIGRATE_VMA_SELECT_DEVICE_PRIVATE) || > page->pgmap->owner != migrate->pgmap_owner) > diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c > index 86e3a3688d59..34230d08556a 100644 > --- a/mm/page_vma_mapped.c > +++ b/mm/page_vma_mapped.c > @@ -96,7 +96,7 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw) > if (!is_migration_entry(entry)) > return false; > > - pfn = migration_entry_to_pfn(entry); > + pfn = swp_offset(entry); > } else if (is_swap_pte(*pvmw->pte)) { > swp_entry_t entry; > > @@ -105,7 +105,7 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw) > if (!is_device_private_entry(entry)) > return false; > > - pfn = device_private_entry_to_pfn(entry); > + pfn = swp_offset(entry); > } else { > if (!pte_present(*pvmw->pte)) > return false; > @@ -200,7 +200,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) > if (is_migration_entry(pmd_to_swp_entry(*pvmw->pmd))) { > swp_entry_t entry = pmd_to_swp_entry(*pvmw->pmd); > > - if (migration_entry_to_page(entry) != page) > + if (pfn_to_page(swp_offset(entry)) != page) > return not_found(pvmw); > return true; > } > -- > 2.20.1 > ---end quoted text---