From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v9 38/61] mm: Convert page migration to XArray Date: Tue, 13 Mar 2018 06:26:16 -0700 Message-ID: <20180313132639.17387-39-willy@infradead.org> References: <20180313132639.17387-1-willy@infradead.org> Return-path: 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=ZP49aq269tFFqpyGMczz8ZSYS9wJPmYPFVNznUUKnms=; b=quuMjzddJh3CvK/i+VkdWSe9Z UilGsfjJoopdWVpx5Exom/YrOMx1cQ3IHtfgTf7gvjCJKoxZwbHlr9IkEKofXwbTR7tY8g0cdIylS ijlN0zy+HOCYwEdLdZEweRqLTtBkKbzfGyyeUAXMlpisY/CUiDLUxb5SIVZcxI4raErPLPN1IIgEt 5gk816xuJ2r0Fd8a/F6+NoHQz6mVzNUn22C/I21krWdXQ2sE8YtrmioGHmB88tkqYOmKjp51u++cg Z53gKv859GBW6s1GepWXtYfO6a8j6EEx2g+AFrf5atk91S/8HcVkFeS0QCtn2gGgGMGXdznBeRUlH In-Reply-To: <20180313132639.17387-1-willy@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: Matthew Wilcox , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ryusuke Konishi , linux-nilfs@vger.kernel.org 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 740b71857898..9a15d27768a0 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->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 @@ -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->i_pages); - - pslot = radix_tree_lookup_slot(&mapping->i_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->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; } @@ -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->i_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->i_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->i_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->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; } @@ -595,11 +586,11 @@ 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; } -- 2.16.1