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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5FAD8C433ED for ; Wed, 28 Apr 2021 04:15:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E719613ED for ; Wed, 28 Apr 2021 04:15:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230364AbhD1EPz (ORCPT ); Wed, 28 Apr 2021 00:15:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:57940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbhD1EPy (ORCPT ); Wed, 28 Apr 2021 00:15:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7D4F7613FF; Wed, 28 Apr 2021 04:15:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619583310; bh=tr3RiEkYUpXM0cW8jK6LjLFqHkkIURxZQlz7091I7Sw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vQu5kofmdeukixE/zMm7Yir71aiZ+Z7SoG8Xn83xeQDwVLKuraZenjVpeQQ58J849 QaSIe+a0WhT6Wr0T3vqndiDHGAzNrCuudyF0frIzj6hdYMy+WM+tC0KMkjra259vqU Zz/hqTvTrzXIEw5/zuugBV74uDdXZzOy/yL0uUXMgRug1/d2ByxL52pwWNlXHaRejD 8N5LpOq6GemD9pDvfRKVwxBNN+QWIqvCvQUmEtcLdt7W9AkAXiGARCc0Qx/HOnLUZp Crq+4FdNtne26gpCFm9tGErMtJ5GI6kvvIvtxLBs6fxoWPgFJK+H+UxMWek9ZS5tG5 fuSYEgdM8JDGQ== Date: Tue, 27 Apr 2021 21:15:09 -0700 From: "Darrick J. Wong" To: Brian Foster Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH v4 2/3] xfs: introduce in-core global counter of allocbt blocks Message-ID: <20210428041509.GH3122264@magnolia> References: <20210423131050.141140-1-bfoster@redhat.com> <20210423131050.141140-3-bfoster@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210423131050.141140-3-bfoster@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Apr 23, 2021 at 09:10:49AM -0400, Brian Foster wrote: > Introduce an in-core counter to track the sum of all allocbt blocks > used by the filesystem. This value is currently tracked per-ag via > the ->agf_btreeblks field in the AGF, which also happens to include > rmapbt blocks. A global, in-core count of allocbt blocks is required > to identify the subset of global ->m_fdblocks that consists of > unavailable blocks currently used for allocation btrees. To support > this calculation at block reservation time, construct a similar > global counter for allocbt blocks, populate it on first read of each > AGF and update it as allocbt blocks are used and released. > > Signed-off-by: Brian Foster > --- > fs/xfs/libxfs/xfs_alloc.c | 12 ++++++++++++ > fs/xfs/libxfs/xfs_alloc_btree.c | 2 ++ > fs/xfs/xfs_mount.h | 6 ++++++ > 3 files changed, 20 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c > index aaa19101bb2a..144e2d68245c 100644 > --- a/fs/xfs/libxfs/xfs_alloc.c > +++ b/fs/xfs/libxfs/xfs_alloc.c > @@ -3036,6 +3036,7 @@ xfs_alloc_read_agf( > struct xfs_agf *agf; /* ag freelist header */ > struct xfs_perag *pag; /* per allocation group data */ > int error; > + uint32_t allocbt_blks; > > trace_xfs_alloc_read_agf(mp, agno); > > @@ -3066,6 +3067,17 @@ xfs_alloc_read_agf( > pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level); > pag->pagf_init = 1; > pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf); > + > + /* > + * Update the global in-core allocbt block counter. Filter > + * rmapbt blocks from the on-disk counter because those are > + * managed by perag reservation. > + */ > + if (pag->pagf_btreeblks > be32_to_cpu(agf->agf_rmap_blocks)) { As pointed out elsewhere in the thread, agf_rmap_blocks counts the total number of blocks in the rmapbt (whereas agf_btreeblks counts the number of non-root blocks in all three free space btrees). Does this need a change? int delta = (int)pag->pagf_btreeblks - (be32_to_cpu(...) - 1); if (delta > 0) atomic64_add(delta, &mp->m_allocbt_blks); --D > + allocbt_blks = pag->pagf_btreeblks - > + be32_to_cpu(agf->agf_rmap_blocks); > + atomic64_add(allocbt_blks, &mp->m_allocbt_blks); > + } > } > #ifdef DEBUG > else if (!XFS_FORCED_SHUTDOWN(mp)) { > diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c > index 8e01231b308e..9f5a45f7baed 100644 > --- a/fs/xfs/libxfs/xfs_alloc_btree.c > +++ b/fs/xfs/libxfs/xfs_alloc_btree.c > @@ -71,6 +71,7 @@ xfs_allocbt_alloc_block( > return 0; > } > > + atomic64_inc(&cur->bc_mp->m_allocbt_blks); > xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.agno, bno, 1, false); > > xfs_trans_agbtree_delta(cur->bc_tp, 1); > @@ -95,6 +96,7 @@ xfs_allocbt_free_block( > if (error) > return error; > > + atomic64_dec(&cur->bc_mp->m_allocbt_blks); > xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1, > XFS_EXTENT_BUSY_SKIP_DISCARD); > xfs_trans_agbtree_delta(cur->bc_tp, -1); > diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h > index 81829d19596e..bb67274ee23f 100644 > --- a/fs/xfs/xfs_mount.h > +++ b/fs/xfs/xfs_mount.h > @@ -170,6 +170,12 @@ typedef struct xfs_mount { > * extents or anything related to the rt device. > */ > struct percpu_counter m_delalloc_blks; > + /* > + * Global count of allocation btree blocks in use across all AGs. Only > + * used when perag reservation is enabled. Helps prevent block > + * reservation from attempting to reserve allocation btree blocks. > + */ > + atomic64_t m_allocbt_blks; > > struct radix_tree_root m_perag_tree; /* per-ag accounting info */ > spinlock_t m_perag_lock; /* lock for m_perag_tree */ > -- > 2.26.3 >