From patchwork Wed Jan 17 20:21:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 10171621 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C1822603ED for ; Wed, 17 Jan 2018 20:59:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B246B22A6B for ; Wed, 17 Jan 2018 20:59:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A701322B26; Wed, 17 Jan 2018 20:59:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 45CEC22A6B for ; Wed, 17 Jan 2018 20:59:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754991AbeAQUzF (ORCPT ); Wed, 17 Jan 2018 15:55:05 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:38601 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753633AbeAQUWj (ORCPT ); Wed, 17 Jan 2018 15:22:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=YUZ5beZhx/G3vTo3IKyRIyWwXMWVVFAXucGgYHIieJ8=; b=lE/AQN2OOfEQle3HMBn9P1jWK NEm1V602I8bsknCwDbwh2UoRLXib4V9rTnK/xmp7j1KC1dQIJ/cDfI/Y5nIfLPpPxVlyW24Pz16z3 VQPLoCDVj6jF+EjoYSr3uqbzbx7t9/jz+kzTWdhcBbhijzmR2Q6hfwhFqXsIaYZEKqYnfvlZxg2ix IrkJzEFlohneFqJytue3AZZqSz29hCmf0NkAAhqOfEiMR96R8E96/MFtqcNZkGtBkqBYdz4dlxEpJ b7lvpbJd185lYtFa68d43++a+QqX8j8UIBb1pVvVfiBl1AjaWsSp3m8hnKbKuGikEZWQVOSL3upUK eRBWrnYMg==; Received: from willy by bombadil.infradead.org with local (Exim 4.89 #1 (Red Hat Linux)) id 1ebuEI-0005pj-CC; Wed, 17 Jan 2018 20:22:38 +0000 From: Matthew Wilcox To: linux-kernel@vger.kernel.org Cc: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, Bjorn Andersson , Stefano Stabellini , iommu@lists.linux-foundation.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, intel-gfx@lists.freedesktop.org, cgroups@vger.kernel.org, linux-sh@vger.kernel.org, David Howells Subject: [PATCH v6 36/99] mm: Convert page migration to XArray Date: Wed, 17 Jan 2018 12:21:00 -0800 Message-Id: <20180117202203.19756-37-willy@infradead.org> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180117202203.19756-1-willy@infradead.org> References: <20180117202203.19756-1-willy@infradead.org> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Matthew Wilcox Signed-off-by: Matthew Wilcox --- mm/migrate.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 75d19904dd9a..7122fec9b075 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -322,7 +322,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, page = migration_entry_to_page(entry); /* - * Once radix-tree replacement of page migration started, page_count + * Once page cache replacement of page migration started, page_count * *must* be zero. And, we don't want to call wait_on_page_locked() * against a page without get_page(). * So, we use get_page_unless_zero(), here. Even failed, page fault @@ -437,10 +437,10 @@ int migrate_page_move_mapping(struct address_space *mapping, struct buffer_head *head, enum migrate_mode mode, int extra_count) { + XA_STATE(xas, &mapping->pages, page_index(page)); struct zone *oldzone, *newzone; int dirty; int expected_count = 1 + extra_count; - void **pslot; /* * Device public or private pages have an extra refcount as they are @@ -466,21 +466,16 @@ int migrate_page_move_mapping(struct address_space *mapping, oldzone = page_zone(page); newzone = page_zone(newpage); - xa_lock_irq(&mapping->pages); - - pslot = radix_tree_lookup_slot(&mapping->pages, - page_index(page)); + xas_lock_irq(&xas); expected_count += 1 + page_has_private(page); - if (page_count(page) != expected_count || - radix_tree_deref_slot_protected(pslot, - &mapping->pages.xa_lock) != page) { - xa_unlock_irq(&mapping->pages); + if (page_count(page) != expected_count || xas_load(&xas) != page) { + xas_unlock_irq(&xas); return -EAGAIN; } if (!page_ref_freeze(page, expected_count)) { - xa_unlock_irq(&mapping->pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -494,7 +489,7 @@ int migrate_page_move_mapping(struct address_space *mapping, if (mode == MIGRATE_ASYNC && head && !buffer_migrate_lock_buffers(head, mode)) { page_ref_unfreeze(page, expected_count); - xa_unlock_irq(&mapping->pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -522,7 +517,7 @@ int migrate_page_move_mapping(struct address_space *mapping, SetPageDirty(newpage); } - radix_tree_replace_slot(&mapping->pages, pslot, newpage); + xas_store(&xas, newpage); /* * Drop cache reference from old page by unfreezing @@ -531,7 +526,7 @@ int migrate_page_move_mapping(struct address_space *mapping, */ page_ref_unfreeze(page, expected_count - 1); - xa_unlock(&mapping->pages); + xas_unlock(&xas); /* Leave irq disabled to prevent preemption while updating stats */ /* @@ -571,22 +566,18 @@ EXPORT_SYMBOL(migrate_page_move_mapping); int migrate_huge_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page) { + XA_STATE(xas, &mapping->pages, page_index(page)); int expected_count; - void **pslot; - - xa_lock_irq(&mapping->pages); - - pslot = radix_tree_lookup_slot(&mapping->pages, page_index(page)); + xas_lock_irq(&xas); expected_count = 2 + page_has_private(page); - if (page_count(page) != expected_count || - radix_tree_deref_slot_protected(pslot, &mapping->pages.xa_lock) != page) { - xa_unlock_irq(&mapping->pages); + if (page_count(page) != expected_count || xas_load(&xas) != page) { + xas_unlock_irq(&xas); return -EAGAIN; } if (!page_ref_freeze(page, expected_count)) { - xa_unlock_irq(&mapping->pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -595,11 +586,11 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, get_page(newpage); - radix_tree_replace_slot(&mapping->pages, pslot, newpage); + xas_store(&xas, newpage); page_ref_unfreeze(page, expected_count - 1); - xa_unlock_irq(&mapping->pages); + xas_unlock_irq(&xas); return MIGRATEPAGE_SUCCESS; }