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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no 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 A3F70C433DF for ; Tue, 25 Aug 2020 05:48:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A0122071E for ; Tue, 25 Aug 2020 05:48:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728879AbgHYFsU (ORCPT ); Tue, 25 Aug 2020 01:48:20 -0400 Received: from mx2.suse.de ([195.135.220.15]:50480 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728145AbgHYFsU (ORCPT ); Tue, 25 Aug 2020 01:48:20 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A1C39ACCF for ; Tue, 25 Aug 2020 05:48:49 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v3 0/4] btrfs: basic refactor of btrfs_buffered_write() Date: Tue, 25 Aug 2020 13:48:04 +0800 Message-Id: <20200825054808.16241-1-wqu@suse.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This patchset will refactor btrfs_buffered_write() by: - Extra the nrptrs calculation into one function The main concern here is the batch number of pages. Originally there is a max(nrptrs, 8), which looks so incorrect that my eyes change it to min(nrptrs, 8) automatically. This time we kill that max(nrptrs, 8), and replace it to a fixed size up limit (64K), which should bring the same performance for different page sized. The limit can be changed if the 64K is not large enough for certain buffered write. - Refactor the main loop into process_one_batch() No functional change, just plain refactor. - Remove the again: tag by integrating page and extent locking The new function lock_pages_and_extent() will handle the retry so we don't need the tag any more in the main loop. Changelog: v2: - Fix a bug that ENOSPC error is not returned to user space It's caused by a missing assignment for (copied < 0) branch in the 2nd patch. v3: - Rename get_nr_pages() to calc_nr_pages() - Remove unnecessary parameter for calc_nr_pages() - Change the upper limit of calc_nr_pages() in a separate patch Qu Wenruo (4): btrfs: refactor @nrptrs calculation of btrfs_buffered_write() btrfs: refactor btrfs_buffered_write() into process_one_batch() btrfs: remove the again: tag in process_one_batch() btrfs: avoid allocating unnecessary page pointers fs/btrfs/file.c | 572 ++++++++++++++++++++++++++---------------------- 1 file changed, 305 insertions(+), 267 deletions(-) -- 2.28.0