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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 67D57C71157 for ; Wed, 18 Jun 2025 17:40:46 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4bMrcG3BBSz30Vf; Thu, 19 Jun 2025 03:40:30 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1750268430; cv=none; b=RxwocdI6tapJI7Uhyip890Pjczj3D8CUjMvq2GBGEsKIofe/KCW+POnAIFdsjth+wTEy4GYoFQkkGj9kuFNgFhVhtorK9PyqLfMKn1LagRO4AcWWgL3YsmhDm997RjsZG7R9+6vClleloE3acu3uQ9ykoJts7rm5no6oNmA/9wEdIISqurGAr35WZ5d+G1VGDpTF/R+A7Lqb1qH/2BbnaB0zY2nyTHeMwE+kosBK+LFl+DlgWiP2Bl6ZDyE1FobmXaPzKg4sSn1NHoNv7egfrkBhH0WCj4SQLvi3krHPzmz0Mt4W8zvAnGbbVYsqhR3quUzLsktyG7nVEXDRUiKaLQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1750268430; c=relaxed/relaxed; bh=hwmXAEBDYo8DkjDdp6VkbgoCuZIqYMKAJtJSkdjCkPU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=fIoW0ofz8hrldIVo7/4vAcSVgcbKGjcqps9x5Oy1OgkGMvKWSODvoQJl22B8FynH/imsGsq+Hu6mFFpSih2ZwxVOVGC8deTppDwj70VmM1YrNoVbBNwryZgeWgKIKsis5X6lqyfNiotT1H2vDOO672uVNyIxr45MalmpoLyAWWna/pkVkStzAud4y4AkxWzFFbPpjhwT6bwzSOZ55OSXBN638b2FrRT9F+gSh6RySBlFLEspYB7Tc3N14sBG8o9cT/6TUzlHisZRDqRF/KK01NNQO8smnmtXG2Z+m/McR1ukN2oUdDBmBj0XZi1MqtJupecnvJ/+x65CE5q7XdLJJQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VtXT84gu; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VtXT84gu; dkim-atps=neutral; spf=pass (client-ip=170.10.129.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=dhildenb@redhat.com; receiver=lists.ozlabs.org) smtp.mailfrom=redhat.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VtXT84gu; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VtXT84gu; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=170.10.129.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=dhildenb@redhat.com; receiver=lists.ozlabs.org) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4bMrcF1s2nz2ym2 for ; Thu, 19 Jun 2025 03:40:28 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750268426; 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=hwmXAEBDYo8DkjDdp6VkbgoCuZIqYMKAJtJSkdjCkPU=; b=VtXT84guJX/bFe6+4R8HEgDxvemzwgWxX+0NvwHp+u/CZ0ZRCkrB5tgaDpzclRK+CMxZcy aM8WW3PAyoynyONyhTqX9jMXF6j0nF2j20lWepngFH9hJMqNIs+gZF+aSjdpK1u3zOKJyO 24LLUcEDxiUHnZy2AC+SZQFtt/qhSf8= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750268426; 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=hwmXAEBDYo8DkjDdp6VkbgoCuZIqYMKAJtJSkdjCkPU=; b=VtXT84guJX/bFe6+4R8HEgDxvemzwgWxX+0NvwHp+u/CZ0ZRCkrB5tgaDpzclRK+CMxZcy aM8WW3PAyoynyONyhTqX9jMXF6j0nF2j20lWepngFH9hJMqNIs+gZF+aSjdpK1u3zOKJyO 24LLUcEDxiUHnZy2AC+SZQFtt/qhSf8= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-249-t_O0sHh1P4-D63B3QnkJUg-1; Wed, 18 Jun 2025 13:40:24 -0400 X-MC-Unique: t_O0sHh1P4-D63B3QnkJUg-1 X-Mimecast-MFC-AGG-ID: t_O0sHh1P4-D63B3QnkJUg_1750268423 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-450d244bfabso59186435e9.0 for ; Wed, 18 Jun 2025 10:40:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750268423; x=1750873223; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hwmXAEBDYo8DkjDdp6VkbgoCuZIqYMKAJtJSkdjCkPU=; b=bt+jgxb/hFuq/Ha3orJGYA5cHa/Y4LyxpBl7SkBi6Y3bjIQjLYTd38WxZZ833e6sMi bD8+tH+CJur+jVuypYnMLHTv2wwonXHlTjYi1nyekW6pnWcxUvBYRe9/LtUlj6UiVFxb ShsPVkiQpg8MJx1wBNqbQtZpYyKS+MMZ8VbG26h8ZH1PdNIpWFZUJGAvrYsJjwnGigta lIsVDLP6Ub1KR+l9nb/+JIj6lnnJpr3hoNGBeUi1jQ3MBRJfmck+VTOIqdvkPpSMjkw1 rFQohj6b7ks2V0W5G45q6BNk88b0tVYvdnPkObjHxTidD8TDq8ggWrvMb8+ce7N1cg3C rE/g== X-Forwarded-Encrypted: i=1; AJvYcCUadkS4bEjQXt5XOdhdC0DJQsGZb8lrYD/39jfC/R5pKdHtJOHeQ2xk0Zdf4nFbHy3GWjsUYUA3nzvNmAE=@lists.ozlabs.org X-Gm-Message-State: AOJu0YwxoS0Z3ePxNsX2+0HWJ10Q+EbjXA0wsEQSPUDqbWemGgNKnv0l 2dBXKxbKWzURTijMgJFIW/aJ7bwxDi+WHKQcADmX2G2SZoui26gwmPlK2XjowBHAweYI8IDFqpE GziNRcDMVP7T4sU/5YD0rzEQ1cGNnEA6kofNO9miJh/3awy/qlIEt5psfIkJg4bnavJw= X-Gm-Gg: ASbGnct29vZlHaQnAI4+ST9Yj1/5fP4NKhyvxtuS/VptmjEmy5O0tuNf0pMK3qJZQb3 iTX4QZhor0Q7tPT2YB98Z+PME9upM4dkjKR73zh8h5k5r1vdxhTFZocwyC3ktWkZBHg4KH9o+1S bCJ1DGXn0uW56hrJPoQh+g/wiGLQ8mrkat6vGhR+IkgLBPvKBDPIVEsBQ9kYGr6LpKZM8sQsV4l OfUKfuH+vJsvi5ZDe2VoqefF+BcQ4bIPNJ8xtTZrVkh4th30Cd+QaKsLntCtms3cvIkPuGOlB91 hnUn3SrGuPiDWgrpRkxbq8G/LmKHMzSmQ0NnFB1BFa63bW3mdn2nCwPSFm4zCMfR2opGQDRGzrJ Yu3kRag== X-Received: by 2002:a05:600c:1d8c:b0:43c:e70d:44f0 with SMTP id 5b1f17b1804b1-4533caad0aemr171055335e9.19.1750268422782; Wed, 18 Jun 2025 10:40:22 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFFNY4J8Mn4IFBBexw6iB/8oHFBQjZ0Pcfadu7y3OlxCDXC24glKPTWmaukP08KWSs+L7QyIw== X-Received: by 2002:a05:600c:1d8c:b0:43c:e70d:44f0 with SMTP id 5b1f17b1804b1-4533caad0aemr171055095e9.19.1750268422300; Wed, 18 Jun 2025 10:40:22 -0700 (PDT) Received: from localhost (p200300d82f2d2400405203b5fff94ed0.dip0.t-ipconnect.de. [2003:d8:2f2d:2400:4052:3b5:fff9:4ed0]) by smtp.gmail.com with UTF8SMTPSA id 5b1f17b1804b1-4535ebcecdcsm3339075e9.36.2025.06.18.10.40.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Jun 2025 10:40:21 -0700 (PDT) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux.dev, linux-fsdevel@vger.kernel.org, David Hildenbrand , Andrew Morton , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Jerrin Shaji George , Arnd Bergmann , Greg Kroah-Hartman , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Alexander Viro , Christian Brauner , Jan Kara , Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , "Matthew Wilcox (Oracle)" , Minchan Kim , Sergey Senozhatsky , Brendan Jackman , Johannes Weiner , Jason Gunthorpe , John Hubbard , Peter Xu , Xu Xin , Chengming Zhou , Miaohe Lin , Naoya Horiguchi , Oscar Salvador , Rik van Riel , Harry Yoo , Qi Zheng , Shakeel Butt Subject: [PATCH RFC 02/29] mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize() Date: Wed, 18 Jun 2025 19:39:45 +0200 Message-ID: <20250618174014.1168640-3-david@redhat.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250618174014.1168640-1-david@redhat.com> References: <20250618174014.1168640-1-david@redhat.com> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: jGIPfWZTVRKUN36KMJSZSCK3Q8OgG_klv4jrIl8kIew_1750268423 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Signed-off-by: David Hildenbrand --- arch/powerpc/platforms/pseries/cmm.c | 2 +- drivers/misc/vmw_balloon.c | 3 +- drivers/virtio/virtio_balloon.c | 4 +-- include/linux/balloon_compaction.h | 43 +++++++++++----------------- mm/balloon_compaction.c | 3 +- 5 files changed, 21 insertions(+), 34 deletions(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 5f4037c1d7fe8..5e0a718d1be7b 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -532,7 +532,6 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info, spin_lock_irqsave(&b_dev_info->pages_lock, flags); balloon_page_insert(b_dev_info, newpage); - balloon_page_delete(page); b_dev_info->isolated_pages--; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); @@ -542,6 +541,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info, */ plpar_page_set_active(page); + balloon_page_finalize(page); /* balloon page list reference */ put_page(page); diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index c817d8c216413..6653fc53c951c 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -1778,8 +1778,7 @@ static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info, * @pages_lock . We keep holding @comm_lock since we will need it in a * second. */ - balloon_page_delete(page); - + balloon_page_finalize(page); put_page(page); /* Inflate */ diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 89da052f4f687..e299e18346a30 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -866,15 +866,13 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, tell_host(vb, vb->inflate_vq); /* balloon's page migration 2nd step -- deflate "page" */ - spin_lock_irqsave(&vb_dev_info->pages_lock, flags); - balloon_page_delete(page); - spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags); vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; set_page_pfns(vb, vb->pfns, page); tell_host(vb, vb->deflate_vq); mutex_unlock(&vb->balloon_lock); + balloon_page_finalize(page); put_page(page); /* balloon reference */ return MIGRATEPAGE_SUCCESS; diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h index 5ca2d56996201..b9f19da37b089 100644 --- a/include/linux/balloon_compaction.h +++ b/include/linux/balloon_compaction.h @@ -97,27 +97,6 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, list_add(&page->lru, &balloon->pages); } -/* - * balloon_page_delete - delete a page from balloon's page list and clear - * the page->private assignement accordingly. - * @page : page to be released from balloon's page list - * - * Caller must ensure the page is locked and the spin_lock protecting balloon - * pages list is held before deleting a page from the balloon device. - */ -static inline void balloon_page_delete(struct page *page) -{ - __ClearPageOffline(page); - __ClearPageMovable(page); - set_page_private(page, 0); - /* - * No touch page.lru field once @page has been isolated - * because VM is using the field. - */ - if (!PageIsolated(page)) - list_del(&page->lru); -} - /* * balloon_page_device - get the b_dev_info descriptor for the balloon device * that enqueues the given page. @@ -141,12 +120,6 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, list_add(&page->lru, &balloon->pages); } -static inline void balloon_page_delete(struct page *page) -{ - __ClearPageOffline(page); - list_del(&page->lru); -} - static inline gfp_t balloon_mapping_gfp_mask(void) { return GFP_HIGHUSER; @@ -154,6 +127,22 @@ static inline gfp_t balloon_mapping_gfp_mask(void) #endif /* CONFIG_BALLOON_COMPACTION */ +/* + * balloon_page_finalize - prepare a balloon page that was removed from the + * balloon list for release to the page allocator + * @page: page to be released to the page allocator + * + * Caller must ensure that the page is locked. + */ +static inline void balloon_page_finalize(struct page *page) +{ + if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) { + __ClearPageMovable(page); + set_page_private(page, 0); + } + __ClearPageOffline(page); +} + /* * balloon_page_push - insert a page into a page list. * @head : pointer to list diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index fcb60233aa35d..ec176bdb8a78b 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -94,7 +94,8 @@ size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info, if (!trylock_page(page)) continue; - balloon_page_delete(page); + list_del(&page->lru); + balloon_page_finalize(page); __count_vm_event(BALLOON_DEFLATE); list_add(&page->lru, pages); unlock_page(page); -- 2.49.0