From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D80EC4332F for ; Thu, 14 Dec 2023 13:26:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229892AbjLNN0R (ORCPT ); Thu, 14 Dec 2023 08:26:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1573283AbjLNN0M (ORCPT ); Thu, 14 Dec 2023 08:26:12 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1156B12D; Thu, 14 Dec 2023 05:26:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=Ps3gOgcx63gp+vASNuJqnAAKIBRQ41EfNIZIAmlnf24=; b=uggU3y4fBWiCXTBEHx5MIrT6DE Rwcj/DmIWwKIJXJZeOj39Hyc3qKt59USXtl8gWutaJpmCNidyxQ6JdbypyM9+FdN5lrPD9KwEZBjC FtlmcDdPIF4tVCDzP5y7JZ2LDk7rSLCrikKAfcIYfGXtjjLDftVNDMAMYh3wVTSjui6YmnhR415rt DzXEuEmW7sWLCoskIiHHKwvEUXd/QnwxMxyfWuy0tLZ1Hs4+colIeuHyZBgighO8cIT+xOofAKBIy 3tz2gpPqZj0UbrFi7QCaaokGySo+SS+UDtxSseeUkYK0kUbMCXmiB2B8xFQ4KNF3jiZQp7HGwTomc xPV8yLiA==; Received: from [88.128.88.27] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1rDlj8-000N5b-1T; Thu, 14 Dec 2023 13:26:10 +0000 From: Christoph Hellwig To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Jan Kara , David Howells Subject: [PATCH 05/11] pagevec: Add ability to iterate a queue Date: Thu, 14 Dec 2023 14:25:38 +0100 Message-Id: <20231214132544.376574-6-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231214132544.376574-1-hch@lst.de> References: <20231214132544.376574-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Matthew Wilcox (Oracle)" Add a loop counter inside the folio_batch to let us iterate from 0-nr instead of decrementing nr and treating the batch as a stack. It would generate some very weird and suboptimal I/O patterns for page writeback to iterate over the batch as a stack. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christoph Hellwig --- include/linux/pagevec.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index 87cc678adc850b..fcc06c300a72c3 100644 --- a/include/linux/pagevec.h +++ b/include/linux/pagevec.h @@ -27,6 +27,7 @@ struct folio; */ struct folio_batch { unsigned char nr; + unsigned char i; bool percpu_pvec_drained; struct folio *folios[PAGEVEC_SIZE]; }; @@ -40,12 +41,14 @@ struct folio_batch { static inline void folio_batch_init(struct folio_batch *fbatch) { fbatch->nr = 0; + fbatch->i = 0; fbatch->percpu_pvec_drained = false; } static inline void folio_batch_reinit(struct folio_batch *fbatch) { fbatch->nr = 0; + fbatch->i = 0; } static inline unsigned int folio_batch_count(struct folio_batch *fbatch) @@ -75,6 +78,21 @@ static inline unsigned folio_batch_add(struct folio_batch *fbatch, return folio_batch_space(fbatch); } +/** + * folio_batch_next - Return the next folio to process. + * @fbatch: The folio batch being processed. + * + * Use this function to implement a queue of folios. + * + * Return: The next folio in the queue, or NULL if the queue is empty. + */ +static inline struct folio *folio_batch_next(struct folio_batch *fbatch) +{ + if (fbatch->i == fbatch->nr) + return NULL; + return fbatch->folios[fbatch->i++]; +} + void __folio_batch_release(struct folio_batch *pvec); static inline void folio_batch_release(struct folio_batch *fbatch) -- 2.39.2