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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B17A2C433DF for ; Thu, 13 Aug 2020 17:13:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BCB02078D for ; Thu, 13 Aug 2020 17:13:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726526AbgHMRNS (ORCPT ); Thu, 13 Aug 2020 13:13:18 -0400 Received: from mx2.suse.de ([195.135.220.15]:32956 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726248AbgHMRNS (ORCPT ); Thu, 13 Aug 2020 13:13:18 -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 37F30AFBB; Thu, 13 Aug 2020 17:13:39 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 47EC7DA6EF; Thu, 13 Aug 2020 19:12:14 +0200 (CEST) Date: Thu, 13 Aug 2020 19:12:14 +0200 From: David Sterba To: dsterba@suse.cz, Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com, Nikolay Borisov Subject: Re: [PATCH 15/23] btrfs: use ticketing for data space reservations Message-ID: <20200813171214.GR2026@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com, Nikolay Borisov References: <20200721142234.2680-1-josef@toxicpanda.com> <20200721142234.2680-16-josef@toxicpanda.com> <20200813165144.GQ2026@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200813165144.GQ2026@twin.jikos.cz> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Aug 13, 2020 at 06:51:44PM +0200, David Sterba wrote: > On Tue, Jul 21, 2020 at 10:22:26AM -0400, Josef Bacik wrote: > > +static void priority_reclaim_data_space(struct btrfs_fs_info *fs_info, > > + struct btrfs_space_info *space_info, > > + struct reserve_ticket *ticket, > > + const enum btrfs_flush_state *states, > > + int states_nr) > > +{ > > + int flush_state = 0; > > + int commit_cycles = 2; > > + > > + while (!space_info->full) { > > + flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE); > > + spin_lock(&space_info->lock); > > + if (ticket->bytes == 0) { > > + spin_unlock(&space_info->lock); > > + return; > > + } > > + spin_unlock(&space_info->lock); > > + } > > +again: > > + while (flush_state < states_nr) { > > + u64 flush_bytes = U64_MAX; > > + > > + if (!commit_cycles) { > > + if (states[flush_state] == FLUSH_DELALLOC_WAIT) { > > + flush_state++; > > + continue; > > + } > > + if (states[flush_state] == COMMIT_TRANS) > > + flush_bytes = ticket->bytes; > > + } > > + > > + flush_space(fs_info, space_info, flush_bytes, > > + states[flush_state]); > > + spin_lock(&space_info->lock); > > + if (ticket->bytes == 0) { > > + spin_unlock(&space_info->lock); > > + return; > > + } > > + spin_unlock(&space_info->lock); > > + flush_state++; > > + } > > Actually, the whole logic in this loop could use some human readable > description. There are 2 overlapping loops, one is over the states and > the other are commit cycles, with some state-conditional changes. Never mind, the code gets removed in a later patch.