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 73089C433B4 for ; Wed, 19 May 2021 01:07:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C8836108D for ; Wed, 19 May 2021 01:07:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231283AbhESBI4 (ORCPT ); Tue, 18 May 2021 21:08:56 -0400 Received: from mail107.syd.optusnet.com.au ([211.29.132.53]:48672 "EHLO mail107.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229485AbhESBI4 (ORCPT ); Tue, 18 May 2021 21:08:56 -0400 Received: from dread.disaster.area (pa49-195-118-180.pa.nsw.optusnet.com.au [49.195.118.180]) by mail107.syd.optusnet.com.au (Postfix) with ESMTPS id 199A91140B6B for ; Wed, 19 May 2021 11:07:35 +1000 (AEST) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1ljAgQ-002bE4-0x for linux-xfs@vger.kernel.org; Wed, 19 May 2021 11:07:34 +1000 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1ljAgP-001t4o-PU for linux-xfs@vger.kernel.org; Wed, 19 May 2021 11:07:33 +1000 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH] xfs: use alloc_pages_bulk_array() for buffers Date: Wed, 19 May 2021 11:07:33 +1000 Message-Id: <20210519010733.449999-1-david@fromorbit.com> X-Mailer: git-send-email 2.31.1 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=xcwBwyABtj18PbVNKPPJDQ==:117 a=xcwBwyABtj18PbVNKPPJDQ==:17 a=5FLXtPjwQuUA:10 a=20KFwNOVAAAA:8 a=Zp1x2qE9gxlNiri35MEA: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 | 91 +++++++++++++++++++++--------------------------- 1 file changed, 39 insertions(+), 52 deletions(-) diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 592800c8852f..a6cf607bbc4a 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -276,8 +276,8 @@ _xfs_buf_alloc( * Allocate a page array capable of holding a specified number * of pages, and point the page buf at it. */ -STATIC int -_xfs_buf_get_pages( +static int +xfs_buf_get_pages( struct xfs_buf *bp, int page_count) { @@ -292,8 +292,8 @@ _xfs_buf_get_pages( if (bp->b_pages == NULL) return -ENOMEM; } - memset(bp->b_pages, 0, sizeof(struct page *) * page_count); } + memset(bp->b_pages, 0, sizeof(struct page *) * bp->b_page_count); return 0; } @@ -356,10 +356,10 @@ xfs_buf_allocate_memory( uint flags) { size_t size; - size_t nbytes, offset; + size_t offset; gfp_t gfp_mask = xb_to_gfp(flags); - unsigned short page_count, i; xfs_off_t start, end; + long filled = 0; int error; xfs_km_flags_t kmflag_mask = 0; @@ -405,55 +405,44 @@ xfs_buf_allocate_memory( start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) >> PAGE_SHIFT; - page_count = end - start; - error = _xfs_buf_get_pages(bp, page_count); + error = xfs_buf_get_pages(bp, end - start); 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 (;;) { + int 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; } @@ -950,8 +939,8 @@ xfs_buf_get_uncached( int flags, struct xfs_buf **bpp) { - unsigned long page_count; - int error, i; + unsigned long filled; + int error; struct xfs_buf *bp; DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); @@ -962,17 +951,15 @@ xfs_buf_get_uncached( if (error) goto fail; - page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; - error = _xfs_buf_get_pages(bp, page_count); + error = xfs_buf_get_pages(bp, PAGE_ALIGN(BBTOB(numblks)) >> PAGE_SHIFT); if (error) goto fail_free_buf; - for (i = 0; i < page_count; i++) { - bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); - if (!bp->b_pages[i]) { - error = -ENOMEM; - goto fail_free_mem; - } + filled = alloc_pages_bulk_array(xb_to_gfp(flags), bp->b_page_count, + bp->b_pages); + if (filled != bp->b_page_count) { + error = -ENOMEM; + goto fail_free_mem; } bp->b_flags |= _XBF_PAGES; @@ -988,8 +975,8 @@ xfs_buf_get_uncached( return 0; fail_free_mem: - while (--i >= 0) - __free_page(bp->b_pages[i]); + while (--filled >= 0) + __free_page(bp->b_pages[filled]); _xfs_buf_free_pages(bp); fail_free_buf: xfs_buf_free_maps(bp); -- 2.31.1