From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v14 26/74] page cache: Convert find_get_pages_range to XArray Date: Sat, 16 Jun 2018 19:00:04 -0700 Message-ID: <20180617020052.4759-27-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; 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=DJ+dstBiK4VALgrPZuDMj7L+o/CdChWFWdvZH44f17s=; b=XAQrX3BmrvvE8KgNLLuvl3LFmY hGp3yQQQwEkZg3S/CLpwnZOfPavKkv6GnpgOHDwI+aiyLntF/R20GJF4LxK9vBkZvS9iSR8T5+qBy c9J9NzrzL0sGSsARjvHgx9zNvsu9VDXx0wxLcdWb50wodJOaJSi5JDiECZa9g9mY7TPY=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; 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=DJ+dstBiK4VALgrPZuDMj7L+o/CdChWFWdvZH44f17s=; b=AyHI4ZU/6CrYsCJS5Wy7MtB+eG mvZgpgp04p2+rFeKbO5fqp6xloLzduFb5K5/PNin6t0vqC5D2Se+0rHJlxj6RllN1TExZYsy5jG1H KBGiqOtf0r10GxmlNUKcCQV8890Kdi8fbQFC5Drgyi7jQq4ALcUxXyfjf4+LMISA8Wqs=; 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=DJ+dstBiK4VALgrPZuDMj7L+o/CdChWFWdvZH44f17s=; b=INyNmPzixk4Iz1eA54QXSKCAC LXiTbJfuzUeHSUZOgBVZBiK9SYrHS6o2gb3cXQ0eDvqcxFzV3PcFS6ZLb/03K8TzefDmyOAKMa73m nyvomD5baJtL8um6jdPYkxCEERKUDhfLacbpRrYHV9R8EFevpaw5cPrUEQ/WfCHuxsQiMw/unxQmW f/E6sPBowdhT4+snThknwZULxAD7oLlyLnB0fn51Pp1PlXh4LHNq5ZiEo1ARCOXsPQ+b3mtRoyYND 3No1Tp0zHY5kT8cPmHz/94pc+EFRxrSkPABDskr+YSaNRIjlbgAyAhin6FmNDfH5pNINrjlBvGrHz V3x1PifuQ==; In-Reply-To: <20180617020052.4759-1-willy@infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-nilfs@vger.kernel.org, Jan Kara , Jeff Layton , Jaegeuk Kim , Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, Nicholas Piggin , Ryusuke Konishi , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues The 'end' parameter of the xas_for_each iterator avoids a useless iteration at the end of the range. Signed-off-by: Matthew Wilcox --- mm/filemap.c | 52 +++++++++++++++++++--------------------------------- 1 file changed, 19 insertions(+), 33 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index b49290131e85..019c263bb6be 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1650,64 +1650,50 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, pgoff_t end, unsigned int nr_pages, struct page **pages) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, *start); + struct page *page; unsigned ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, *start) { - struct page *head, *page; - - if (iter.index > end) - break; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each(&xas, page, end) { + struct page *head; + if (xas_retry(&xas, page)) continue; - - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Skip - * over it. - */ + /* Skip over shadow, swap and DAX entries */ + if (xa_is_value(page)) continue; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; pages[ret] = page; if (++ret == nr_pages) { - *start = pages[ret - 1]->index + 1; + *start = page->index + 1; goto out; } + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } /* * We come here when there is no page beyond @end. We take care to not * overflow the index @start as it confuses some of the callers. This - * breaks the iteration when there is page at index -1 but that is + * breaks the iteration when there is a page at index -1 but that is * already broken anyway. */ if (end == (pgoff_t)-1) -- 2.17.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot