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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45100C47088 for ; Wed, 26 May 2021 22:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21520613D3 for ; Wed, 26 May 2021 22:47:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231470AbhEZWtB (ORCPT ); Wed, 26 May 2021 18:49:01 -0400 Received: from mail105.syd.optusnet.com.au ([211.29.132.249]:48464 "EHLO mail105.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234649AbhEZWtA (ORCPT ); Wed, 26 May 2021 18:49:00 -0400 Received: from dread.disaster.area (pa49-180-230-185.pa.nsw.optusnet.com.au [49.180.230.185]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id 6D43F1044749; Thu, 27 May 2021 08:47:26 +1000 (AEST) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1lm2JB-005b8X-Lr; Thu, 27 May 2021 08:47:25 +1000 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1lm2JB-004fAE-EG; Thu, 27 May 2021 08:47:25 +1000 From: Dave Chinner To: linux-xfs@vger.kernel.org Cc: hch@lst.de Subject: [PATCH 03/10] xfs: use alloc_pages_bulk_array() for buffers Date: Thu, 27 May 2021 08:47:15 +1000 Message-Id: <20210526224722.1111377-4-david@fromorbit.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210526224722.1111377-1-david@fromorbit.com> References: <20210526224722.1111377-1-david@fromorbit.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=F8MpiZpN c=1 sm=1 tr=0 a=dUIOjvib2kB+GiIc1vUx8g==:117 a=dUIOjvib2kB+GiIc1vUx8g==:17 a=5FLXtPjwQuUA:10 a=20KFwNOVAAAA:8 a=KeS95dpyy_nX3SypCP0A:9 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner Because it's more efficient than allocating pages one at a time in a loop. Signed-off-by: Dave Chinner --- fs/xfs/xfs_buf.c | 62 +++++++++++++++++++----------------------------- 1 file changed, 24 insertions(+), 38 deletions(-) diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index b1610115d401..8ca4add138c5 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -386,10 +386,7 @@ xfs_buf_alloc_pages( xfs_buf_flags_t flags) { gfp_t gfp_mask = xb_to_gfp(flags); - size_t size; - size_t offset; - size_t nbytes; - int i; + long filled = 0; int error; /* Assure zeroed buffer for non-read cases. */ @@ -400,50 +397,39 @@ xfs_buf_alloc_pages( if (unlikely(error)) return error; - offset = bp->b_offset; bp->b_flags |= _XBF_PAGES; - for (i = 0; i < bp->b_page_count; i++) { - struct page *page; - uint retries = 0; -retry: - page = alloc_page(gfp_mask); - if (unlikely(page == NULL)) { - if (flags & XBF_READ_AHEAD) { - bp->b_page_count = i; - error = -ENOMEM; - goto out_free_pages; - } + /* + * Bulk filling of pages can take multiple calls. Not filling the entire + * array is not an allocation failure, so don't back off if we get at + * least one extra page. + */ + for (;;) { + long last = filled; - /* - * This could deadlock. - * - * But until all the XFS lowlevel code is revamped to - * handle buffer allocation failures we can't do much. - */ - if (!(++retries % 100)) - xfs_err(NULL, - "%s(%u) possible memory allocation deadlock in %s (mode:0x%x)", - current->comm, current->pid, - __func__, gfp_mask); - - XFS_STATS_INC(bp->b_mount, xb_page_retries); - congestion_wait(BLK_RW_ASYNC, HZ/50); - goto retry; + filled = alloc_pages_bulk_array(gfp_mask, bp->b_page_count, + bp->b_pages); + if (filled == bp->b_page_count) { + XFS_STATS_INC(bp->b_mount, xb_page_found); + break; } - XFS_STATS_INC(bp->b_mount, xb_page_found); + if (filled != last) + continue; - nbytes = min_t(size_t, size, PAGE_SIZE - offset); - size -= nbytes; - bp->b_pages[i] = page; - offset = 0; + if (flags & XBF_READ_AHEAD) { + error = -ENOMEM; + goto out_free_pages; + } + + XFS_STATS_INC(bp->b_mount, xb_page_retries); + congestion_wait(BLK_RW_ASYNC, HZ/50); } return 0; out_free_pages: - for (i = 0; i < bp->b_page_count; i++) - __free_page(bp->b_pages[i]); + while (--filled >= 0) + __free_page(bp->b_pages[filled]); bp->b_flags &= ~_XBF_PAGES; return error; } -- 2.31.1