From patchwork Fri May 18 16:48:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10411643 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 2744F601F9 for ; Fri, 18 May 2018 17:02:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 173A128A00 for ; Fri, 18 May 2018 17:02:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0C69628A0D; Fri, 18 May 2018 17:02:44 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham 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 8A345289F6 for ; Fri, 18 May 2018 17:02:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752103AbeERQtD (ORCPT ); Fri, 18 May 2018 12:49:03 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:49800 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751976AbeERQs4 (ORCPT ); Fri, 18 May 2018 12:48:56 -0400 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=oSP2hVLP8N4RXip75swrSdvJquBJcH7X+visgc8Cb2k=; b=B3I9hxjFKY/7I9GVyz86UIUVe sFCuL16Plildiz/QhsEz9w7tmxJ9twWXcdc3hKfQgFU1RnEhpGYR44YgLoYXadba+tt4YNTFHHRN/ Qy2HBi0aX1CalX1hss6piGWEaiqQCwXhg/qk9XKJ7El1u/CkUT5AmTfwRZevxIrW2qJ89/uv/GHyu dTajkZfOaEG9z/oFdRkUwDwAemqenlk5ycjWZOuz1orwlz+rRkfYBjI9x/K13wSQ0+Jd897FyGzCw BL7xGbWfLRZRj2iEL3jZVKMsQFeiLXumCMpyD+pzBV0xvHsYae+1/XlFOEVE7ZFnYLCiFp09cQR9F AdlM/WTLA==; Received: from 80-109-164-210.cable.dynamic.surfer.at ([80.109.164.210] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fJiYp-0006Ul-QS; Fri, 18 May 2018 16:48:56 +0000 From: Christoph Hellwig To: linux-xfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 08/34] mm: split ->readpages calls to avoid non-contiguous pages lists Date: Fri, 18 May 2018 18:48:04 +0200 Message-Id: <20180518164830.1552-9-hch@lst.de> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180518164830.1552-1-hch@lst.de> References: <20180518164830.1552-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP That way file systems don't have to go spotting for non-contiguous pages and work around them. It also kicks off I/O earlier, allowing it to finish earlier and reduce latency. Signed-off-by: Christoph Hellwig --- mm/readahead.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/mm/readahead.c b/mm/readahead.c index fa4d4b767130..044ab0c137cc 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -177,8 +177,18 @@ unsigned int __do_page_cache_readahead(struct address_space *mapping, rcu_read_lock(); page = radix_tree_lookup(&mapping->i_pages, page_offset); rcu_read_unlock(); - if (page && !radix_tree_exceptional_entry(page)) + if (page && !radix_tree_exceptional_entry(page)) { + /* + * Page already present? Kick off the current batch of + * contiguous pages before continuing with the next + * batch. + */ + if (nr_pages) + read_pages(mapping, filp, &page_pool, nr_pages, + gfp_mask); + nr_pages = 0; continue; + } page = __page_cache_alloc(gfp_mask); if (!page)