From patchwork Mon Jun 12 20:39:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matthew Wilcox (Oracle)" X-Patchwork-Id: 13277323 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 213CEC88CBB for ; Mon, 12 Jun 2023 20:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229765AbjFLUkK (ORCPT ); Mon, 12 Jun 2023 16:40:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235111AbjFLUjn (ORCPT ); Mon, 12 Jun 2023 16:39:43 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 966B5E55; Mon, 12 Jun 2023 13:39:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=c8745NcmMaAp/1V7qpVz2YDyTLW0s05GpZrPgABIB0g=; b=WPpq4Uloueb/78nVMjfKJzzHwD HxKhRwobRRAUvaiMilIOu7Ej8vYW/amSpLiV15DlJOWvRe41GyMnd6FNYkYA078G//UDbHsf+vGcb oHQbkQh5sWOrOkOXr3QeneosBepNpZJAmWVMGCsbi8rkSDWKFB0tG5M62bkJY4059rUYVGRad5Q+3 NMw0C9uJBJiVcxUEmh6ynZCKNeyaFF1vzlLGPxBJry2pLFngr7IoDDbqHNsiks2jF0vlaklvOOBwc MNn9xiMQTH9Cp347iZpZIJ/wrFThierZwx49d4YN6pwep0++1CcTYxTeW+kDjj1V9JwZLbnwseVlM F833eMQg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1q8oJl-0032ST-8X; Mon, 12 Jun 2023 20:39:13 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-xfs@vger.kernel.org, Wang Yugui , Dave Chinner , Christoph Hellwig , "Darrick J . Wong" Subject: [PATCH v3 0/8] Create large folios in iomap buffered write path Date: Mon, 12 Jun 2023 21:39:02 +0100 Message-Id: <20230612203910.724378-1-willy@infradead.org> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Commit ebb7fb1557b1 limited the length of ioend chains to 4096 entries to improve worst-case latency. Unfortunately, this had the effect of limiting the performance of: fio -name write-bandwidth -rw=write -bs=1024Ki -size=32Gi -runtime=30 \ -iodepth 1 -ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 \ -numjobs=4 -directory=/mnt/test The problem ends up being lock contention on the i_pages spinlock as we clear the writeback bit on each folio (and propagate that up through the tree). By using larger folios, we decrease the number of folios to be processed by a factor of 256 for this benchmark, eliminating the lock contention. It's also the right thing to do. This is a project that has been on the back burner for years, it just hasn't been important enough to do before now. I think it's probably best if this goes through the iomap tree since the changes outside iomap are either to the page cache or they're trivial. v3: - Fix the handling of compound highmem pages in copy_page_from_iter_atomic() - Rename fgp_t to fgf_t - Clarify some wording in the documentation v2: - Fix misplaced semicolon - Rename fgp_order to fgp_set_order - Rename FGP_ORDER to FGP_GET_ORDER - Add fgp_t - Update the documentation for ->release_folio - Fix iomap_invalidate_folio() - Update iomap_release_folio() Matthew Wilcox (Oracle) (8): iov_iter: Handle compound highmem pages in copy_page_from_iter_atomic() iomap: Remove large folio handling in iomap_invalidate_folio() doc: Correct the description of ->release_folio iomap: Remove unnecessary test from iomap_release_folio() filemap: Add fgf_t typedef filemap: Allow __filemap_get_folio to allocate large folios iomap: Create large folios in the buffered write path iomap: Copy larger chunks from userspace Documentation/filesystems/locking.rst | 15 ++++-- fs/btrfs/file.c | 6 +-- fs/f2fs/compress.c | 2 +- fs/f2fs/f2fs.h | 2 +- fs/gfs2/bmap.c | 2 +- fs/iomap/buffered-io.c | 43 ++++++++-------- include/linux/iomap.h | 2 +- include/linux/pagemap.h | 71 ++++++++++++++++++++++----- lib/iov_iter.c | 43 ++++++++++------ mm/filemap.c | 61 ++++++++++++----------- mm/folio-compat.c | 2 +- mm/readahead.c | 13 ----- 12 files changed, 159 insertions(+), 103 deletions(-)