From patchwork Mon Dec 11 15:56:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13487477 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 3A6B7C4167B for ; Mon, 11 Dec 2023 15:58:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 014ED6B0140; Mon, 11 Dec 2023 10:58:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F06726B0142; Mon, 11 Dec 2023 10:58:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D586E6B0143; Mon, 11 Dec 2023 10:58:38 -0500 (EST) 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 BF0636B0140 for ; Mon, 11 Dec 2023 10:58:38 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 95E3C1A072C for ; Mon, 11 Dec 2023 15:58:38 +0000 (UTC) X-FDA: 81554995116.06.DFC36CB Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf04.hostedemail.com (Postfix) with ESMTP id D6D7240013 for ; Mon, 11 Dec 2023 15:58:36 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XlnTavQR; spf=pass (imf04.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702310316; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lJSSYac1nr+7xVv+4BgklrjvdDaeoEoSEBfa7pAELWg=; b=59z3v5Q+P8bHnmEUY/TM51C75lwW3D8NjjskaNiVET7RXE2rkYxig3i51ntxRmaLGoCNif JkzSKIZxNmmW+tCdPbXP14spKkpa/4aEARrJJ+At4yYwht91VJUy3LEnl3PQTcHASN7PZX sUYr6SKweiLpM7I+5SYtO7RaitA+WHI= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702310316; a=rsa-sha256; cv=none; b=ZD3g3wbvqt8VoZZHGh+aBUwLz9uxG0FZAZqYNmvPYPiqm7JcOREjKyO0O8mK1APRlpwtYf 7/wOl6VK8/6fTg+im5IlLEh73lI3iJI5El//880Sd6lxmVT9VPkaFoE7jQ1GcmEs8CQ2Jg JnKHKZAJ1OwrfvtrH1JCaLH6di9RNY0= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XlnTavQR; spf=pass (imf04.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702310316; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lJSSYac1nr+7xVv+4BgklrjvdDaeoEoSEBfa7pAELWg=; b=XlnTavQRqdWzVj+4MvPJbXjjkfsqJsfcZ9KJZ5tlHG4bAO0IvMcRu1UmGD6gnNnocmRCrA c8R0o0pZCAQvuEdEswjffvq7SqzOVjt7c/3YOCg/JoKCiI1VHPzL7YnRrUkuSEDvryn0P1 5fwpR6kMUYx1unkPSmO1zs/xUnkibvE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-616-cwKjNob0OqmmW5y0fjpgYA-1; Mon, 11 Dec 2023 10:58:33 -0500 X-MC-Unique: cwKjNob0OqmmW5y0fjpgYA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B6830185A787; Mon, 11 Dec 2023 15:58:32 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.192.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 14FA71121306; Mon, 11 Dec 2023 15:58:30 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Andrew Morton , "Matthew Wilcox (Oracle)" , Hugh Dickins , Ryan Roberts , Yin Fengwei , Mike Kravetz , Muchun Song , Peter Xu Subject: [PATCH v1 38/39] mm: convert page_try_share_anon_rmap() to folio_try_share_anon_rmap_[pte|pmd]() Date: Mon, 11 Dec 2023 16:56:51 +0100 Message-ID: <20231211155652.131054-39-david@redhat.com> In-Reply-To: <20231211155652.131054-1-david@redhat.com> References: <20231211155652.131054-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Rspamd-Queue-Id: D6D7240013 X-Rspam-User: X-Stat-Signature: mq979hfzzfh7qx1gydnqxpxqgi4sf7fu X-Rspamd-Server: rspam03 X-HE-Tag: 1702310316-158253 X-HE-Meta: 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 esNTiC+9 SBoGdFIg7EQxdfgggVYFtJrfc0Ay9+C22f0+68Z+NnkX7enWO91oyLJM7I4btybZMdp62bh14gu+hvjkGMYfnMT/JLKJ1kffmJcWoeifyck/DC3wuvh3tvgRX/9a+D9Oj/bZp24SWxopsQ77q0Cn09jEDjpSFW8ctVoPl14DwX0OYCH25rspdi+oCCqWzJ30uRSQcrJVLxeVGfdb200PTP62SN58PySGTGsn6 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: Let's convert it like we converted all the other rmap functions. Don't introduce folio_try_share_anon_rmap_ptes() for now, as we don't have a user that wants rmap batching in sight. Pretty easy to add later. All users are easy to convert -- only ksm.c doesn't use folios yet but that is left for future work -- so let's just do it in a single shot. While at it, turn the BUG_ON into a WARN_ON_ONCE. Note that page_try_share_anon_rmap() so far didn't care about pte/pmd mappings (no compound parameter). We're changing that so we can perform better sanity checks and make the code actually more readable/consistent. For example, __folio_rmap_sanity_checks() will make sure that a PMD range actually falls completely into the folio. Signed-off-by: David Hildenbrand --- include/linux/rmap.h | 95 +++++++++++++++++++++++++++++++++----------- mm/gup.c | 2 +- mm/huge_memory.c | 9 +++-- mm/internal.h | 4 +- mm/ksm.c | 5 ++- mm/migrate_device.c | 2 +- mm/rmap.c | 11 ++--- 7 files changed, 89 insertions(+), 39 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 1e37ee6ae0ba..1e54a28cc884 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -272,7 +272,7 @@ static inline int hugetlb_try_dup_anon_rmap(struct folio *folio, return 0; } -/* See page_try_share_anon_rmap() */ +/* See folio_try_share_anon_rmap_*() */ static inline int hugetlb_try_share_anon_rmap(struct folio *folio) { VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio); @@ -481,30 +481,15 @@ static inline int folio_try_dup_anon_rmap_pmd(struct folio *folio, #endif } -/** - * page_try_share_anon_rmap - try marking an exclusive anonymous page possibly - * shared to prepare for KSM or temporary unmapping - * @page: the exclusive anonymous page to try marking possibly shared - * - * The caller needs to hold the PT lock and has to have the page table entry - * cleared/invalidated. - * - * This is similar to folio_try_dup_anon_rmap_*(), however, not used during - * fork() to duplicate a mapping, but instead to prepare for KSM or temporarily - * unmapping a page (swap, migration) via folio_remove_rmap_*(). - * - * Marking the page shared can only fail if the page may be pinned; device - * private pages cannot get pinned and consequently this function cannot fail. - * - * Returns 0 if marking the page possibly shared succeeded. Returns -EBUSY - * otherwise. - */ -static inline int page_try_share_anon_rmap(struct page *page) +static __always_inline int __folio_try_share_anon_rmap(struct folio *folio, + struct page *page, int nr_pages, enum rmap_mode mode) { - VM_BUG_ON_PAGE(!PageAnon(page) || !PageAnonExclusive(page), page); + VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio); + VM_WARN_ON_FOLIO(!PageAnonExclusive(page), folio); + __folio_rmap_sanity_checks(folio, page, nr_pages, mode); - /* device private pages cannot get pinned via GUP. */ - if (unlikely(is_device_private_page(page))) { + /* device private folios cannot get pinned via GUP. */ + if (unlikely(folio_is_device_private(folio))) { ClearPageAnonExclusive(page); return 0; } @@ -555,7 +540,7 @@ static inline int page_try_share_anon_rmap(struct page *page) if (IS_ENABLED(CONFIG_HAVE_FAST_GUP)) smp_mb(); - if (unlikely(page_maybe_dma_pinned(page))) + if (unlikely(folio_maybe_dma_pinned(folio))) return -EBUSY; ClearPageAnonExclusive(page); @@ -568,6 +553,68 @@ static inline int page_try_share_anon_rmap(struct page *page) return 0; } +/** + * folio_try_share_anon_rmap_pte - try marking an exclusive anonymous page + * mapped by a PTE possibly shared to prepare + * for KSM or temporary unmapping + * @folio: The folio to share a mapping of + * @page: The mapped exclusive page + * + * The caller needs to hold the page table lock and has to have the page table + * entries cleared/invalidated. + * + * This is similar to folio_try_dup_anon_rmap_pte(), however, not used during + * fork() to duplicate mappings, but instead to prepare for KSM or temporarily + * unmapping parts of a folio (swap, migration) via folio_remove_rmap_pte(). + * + * Marking the mapped page shared can only fail if the folio maybe pinned; + * device private folios cannot get pinned and consequently this function cannot + * fail. + * + * Returns 0 if marking the mapped page possibly shared succeeded. Returns + * -EBUSY otherwise. + */ +static inline int folio_try_share_anon_rmap_pte(struct folio *folio, + struct page *page) +{ + return __folio_try_share_anon_rmap(folio, page, 1, RMAP_MODE_PTE); +} + +/** + * folio_try_share_anon_rmap_pmd - try marking an exclusive anonymous page + * range mapped by a PMD possibly shared to + * prepare for temporary unmapping + * @folio: The folio to share the mapping of + * @page: The first page to share the mapping of + * + * The page range of the folio is defined by [page, page + HPAGE_PMD_NR) + * + * The caller needs to hold the page table lock and has to have the page table + * entries cleared/invalidated. + * + * This is similar to folio_try_dup_anon_rmap_pmd(), however, not used during + * fork() to duplicate a mapping, but instead to prepare for temporarily + * unmapping parts of a folio (swap, migration) via folio_remove_rmap_pmd(). + * + * Marking the mapped pages shared can only fail if the folio maybe pinned; + * device private folios cannot get pinned and consequently this function cannot + * fail. + * + * Returns 0 if marking the mapped pages possibly shared succeeded. Returns + * -EBUSY otherwise. + */ +static inline int folio_try_share_anon_rmap_pmd(struct folio *folio, + struct page *page) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + return __folio_try_share_anon_rmap(folio, page, HPAGE_PMD_NR, + RMAP_MODE_PMD); +#else + WARN_ON_ONCE(true); + return -EBUSY; +#endif +} + /* * Called from mm/vmscan.c to handle paging out */ diff --git a/mm/gup.c b/mm/gup.c index 0a5f0e91bfec..df83182ec72d 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -177,7 +177,7 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags) /* * Adjust the pincount before re-checking the PTE for changes. * This is essentially a smp_mb() and is paired with a memory - * barrier in page_try_share_anon_rmap(). + * barrier in folio_try_share_anon_rmap_*(). */ smp_mb__after_atomic(); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 34f878916621..c681296fa429 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2523,10 +2523,11 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, * In case we cannot clear PageAnonExclusive(), split the PMD * only and let try_to_migrate_one() fail later. * - * See page_try_share_anon_rmap(): invalidate PMD first. + * See folio_try_share_anon_rmap_pmd(): invalidate PMD first. */ anon_exclusive = PageAnonExclusive(page); - if (freeze && anon_exclusive && page_try_share_anon_rmap(page)) + if (freeze && anon_exclusive && + folio_try_share_anon_rmap_pmd(folio, page)) freeze = false; if (!freeze) { rmap_t rmap_flags = RMAP_NONE; @@ -3554,9 +3555,9 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); pmdval = pmdp_invalidate(vma, address, pvmw->pmd); - /* See page_try_share_anon_rmap(): invalidate PMD first. */ + /* See folio_try_share_anon_rmap_pmd(): invalidate PMD first. */ anon_exclusive = folio_test_anon(folio) && PageAnonExclusive(page); - if (anon_exclusive && page_try_share_anon_rmap(page)) { + if (anon_exclusive && folio_try_share_anon_rmap_pmd(folio, page)) { set_pmd_at(mm, address, pvmw->pmd, pmdval); return -EBUSY; } diff --git a/mm/internal.h b/mm/internal.h index a94355e70bd7..29589bc3f046 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1047,7 +1047,7 @@ enum { * * Ordinary GUP: Using the PT lock * * GUP-fast and fork(): mm->write_protect_seq * * GUP-fast and KSM or temporary unmapping (swap, migration): see - * page_try_share_anon_rmap() + * folio_try_share_anon_rmap_*() * * Must be called with the (sub)page that's actually referenced via the * page table entry, which might not necessarily be the head page for a @@ -1090,7 +1090,7 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma, return is_cow_mapping(vma->vm_flags); } - /* Paired with a memory barrier in page_try_share_anon_rmap(). */ + /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */ if (IS_ENABLED(CONFIG_HAVE_FAST_GUP)) smp_rmb(); diff --git a/mm/ksm.c b/mm/ksm.c index b3d0cfaa2533..be76e9dabf4f 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1161,8 +1161,9 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, goto out_unlock; } - /* See page_try_share_anon_rmap(): clear PTE first. */ - if (anon_exclusive && page_try_share_anon_rmap(page)) { + /* See folio_try_share_anon_rmap_pte(): clear PTE first. */ + if (anon_exclusive && + folio_try_share_anon_rmap_pte(page_folio(page), page)) { set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } diff --git a/mm/migrate_device.c b/mm/migrate_device.c index c51c99151ebb..9d0c1ad73722 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -202,7 +202,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, if (anon_exclusive) { pte = ptep_clear_flush(vma, addr, ptep); - if (page_try_share_anon_rmap(page)) { + if (folio_try_share_anon_rmap_pte(folio, page)) { set_pte_at(mm, addr, ptep, pte); folio_unlock(folio); folio_put(folio); diff --git a/mm/rmap.c b/mm/rmap.c index b08dd7d6779d..45296739236f 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1868,9 +1868,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, break; } - /* See page_try_share_anon_rmap(): clear PTE first. */ + /* See folio_try_share_anon_rmap(): clear PTE first. */ if (anon_exclusive && - page_try_share_anon_rmap(subpage)) { + folio_try_share_anon_rmap_pte(folio, subpage)) { swap_free(entry); set_pte_at(mm, address, pvmw.pte, pteval); ret = false; @@ -2144,7 +2144,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, pte_t swp_pte; if (anon_exclusive) - BUG_ON(page_try_share_anon_rmap(subpage)); + WARN_ON_ONCE(folio_try_share_anon_rmap_pte(folio, + subpage)); /* * Store the pfn of the page in a special migration @@ -2215,7 +2216,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, VM_BUG_ON_PAGE(pte_write(pteval) && folio_test_anon(folio) && !anon_exclusive, subpage); - /* See page_try_share_anon_rmap(): clear PTE first. */ + /* See folio_try_share_anon_rmap_pte(): clear PTE first. */ if (folio_test_hugetlb(folio)) { if (anon_exclusive && hugetlb_try_share_anon_rmap(folio)) { @@ -2226,7 +2227,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, break; } } else if (anon_exclusive && - page_try_share_anon_rmap(subpage)) { + folio_try_share_anon_rmap_pte(folio, subpage)) { set_pte_at(mm, address, pvmw.pte, pteval); ret = false; page_vma_mapped_walk_done(&pvmw);