From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 6F5B36B0277 for ; Sat, 16 Jun 2018 22:01:07 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id z5-v6so7705701pln.20 for ; Sat, 16 Jun 2018 19:01:07 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id o124-v6si9218244pga.90.2018.06.16.19.01.06 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 16 Jun 2018 19:01:06 -0700 (PDT) From: Matthew Wilcox Subject: [PATCH v14 41/74] mm: Convert page migration to XArray Date: Sat, 16 Jun 2018 19:00:19 -0700 Message-Id: <20180617020052.4759-42-willy@infradead.org> In-Reply-To: <20180617020052.4759-1-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , Jan Kara , Jeff Layton , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues , Nicholas Piggin , Ryusuke Konishi , linux-nilfs@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Signed-off-by: Matthew Wilcox --- mm/migrate.c | 48 ++++++++++++++++++------------------------------ 1 file changed, 18 insertions(+), 30 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 8c0af0f7cab1..80dc5b8c9738 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -323,7 +323,7 @@ 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 @@ -438,10 +438,10 @@ int migrate_page_move_mapping(struct address_space *mapping, struct buffer_head *head, enum migrate_mode mode, int extra_count) { + XA_STATE(xas, &mapping->i_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 @@ -467,21 +467,16 @@ int migrate_page_move_mapping(struct address_space *mapping, oldzone = page_zone(page); newzone = page_zone(newpage); - xa_lock_irq(&mapping->i_pages); - - pslot = radix_tree_lookup_slot(&mapping->i_pages, - page_index(page)); + xas_lock_irq(&xas); expected_count += hpage_nr_pages(page) + page_has_private(page); - if (page_count(page) != expected_count || - radix_tree_deref_slot_protected(pslot, - &mapping->i_pages.xa_lock) != page) { - xa_unlock_irq(&mapping->i_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->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -495,7 +490,7 @@ 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->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -523,16 +518,13 @@ int migrate_page_move_mapping(struct address_space *mapping, SetPageDirty(newpage); } - radix_tree_replace_slot(&mapping->i_pages, pslot, newpage); + xas_store(&xas, newpage); if (PageTransHuge(page)) { int i; - int index = page_index(page); for (i = 1; i < HPAGE_PMD_NR; i++) { - pslot = radix_tree_lookup_slot(&mapping->i_pages, - index + i); - radix_tree_replace_slot(&mapping->i_pages, pslot, - newpage + i); + xas_next(&xas); + xas_store(&xas, newpage + i); } } @@ -543,7 +535,7 @@ int migrate_page_move_mapping(struct address_space *mapping, */ page_ref_unfreeze(page, expected_count - hpage_nr_pages(page)); - xa_unlock(&mapping->i_pages); + xas_unlock(&xas); /* Leave irq disabled to prevent preemption while updating stats */ /* @@ -583,22 +575,18 @@ 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->i_pages, page_index(page)); int expected_count; - void **pslot; - - xa_lock_irq(&mapping->i_pages); - - pslot = radix_tree_lookup_slot(&mapping->i_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->i_pages.xa_lock) != page) { - xa_unlock_irq(&mapping->i_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->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -607,11 +595,11 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, get_page(newpage); - radix_tree_replace_slot(&mapping->i_pages, pslot, newpage); + xas_store(&xas, newpage); page_ref_unfreeze(page, expected_count - 1); - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); return MIGRATEPAGE_SUCCESS; } -- 2.17.1