From patchwork Thu Jun 4 07:45:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 11587239 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A10D6159A for ; Thu, 4 Jun 2020 07:46:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 930852067B for ; Thu, 4 Jun 2020 07:46:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727854AbgFDHqN (ORCPT ); Thu, 4 Jun 2020 03:46:13 -0400 Received: from mail106.syd.optusnet.com.au ([211.29.132.42]:49522 "EHLO mail106.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727058AbgFDHqN (ORCPT ); Thu, 4 Jun 2020 03:46:13 -0400 Received: from dread.disaster.area (pa49-180-124-177.pa.nsw.optusnet.com.au [49.180.124.177]) by mail106.syd.optusnet.com.au (Postfix) with ESMTPS id 41BE95AACE2 for ; Thu, 4 Jun 2020 17:46:10 +1000 (AEST) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1jgkZk-0004Af-7O for linux-xfs@vger.kernel.org; Thu, 04 Jun 2020 17:46:08 +1000 Received: from dave by discord.disaster.area with local (Exim 4.93) (envelope-from ) id 1jgkZj-0017Hz-VE for linux-xfs@vger.kernel.org; Thu, 04 Jun 2020 17:46:07 +1000 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH 19/30] xfs: allow multiple reclaimers per AG Date: Thu, 4 Jun 2020 17:45:55 +1000 Message-Id: <20200604074606.266213-20-david@fromorbit.com> X-Mailer: git-send-email 2.26.2.761.g0e0b3e54be In-Reply-To: <20200604074606.266213-1-david@fromorbit.com> References: <20200604074606.266213-1-david@fromorbit.com> MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=QIgWuTDL c=1 sm=1 tr=0 a=k3aV/LVJup6ZGWgigO6cSA==:117 a=k3aV/LVJup6ZGWgigO6cSA==:17 a=nTHF0DUjJn0A:10 a=20KFwNOVAAAA:8 a=yPCof4ZbAAAA:8 a=vMY9R6GoBIkpaNy9teYA:9 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner Inode reclaim will still throttle direct reclaim on the per-ag reclaim locks. This is no longer necessary as reclaim can run non-blocking now. Hence we can remove these locks so that we don't arbitrarily block reclaimers just because there are more direct reclaimers than there are AGs. This can result in multiple reclaimers working on the same range of an AG, but this doesn't cause any apparent issues. Optimising the spread of concurrent reclaimers for best efficiency can be done in a future patchset. Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Reviewed-by: Brian Foster --- fs/xfs/xfs_icache.c | 31 ++++++++++++------------------- fs/xfs/xfs_mount.c | 4 ---- fs/xfs/xfs_mount.h | 1 - 3 files changed, 12 insertions(+), 24 deletions(-) diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 74032316ce5cc..c4ba8d7bc45bc 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -1211,12 +1211,9 @@ xfs_reclaim_inodes_ag( int *nr_to_scan) { struct xfs_perag *pag; - xfs_agnumber_t ag; - int trylock = flags & SYNC_TRYLOCK; - int skipped; + xfs_agnumber_t ag = 0; + int skipped = 0; - ag = 0; - skipped = 0; while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) { unsigned long first_index = 0; int done = 0; @@ -1224,15 +1221,13 @@ xfs_reclaim_inodes_ag( ag = pag->pag_agno + 1; - if (trylock) { - if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) { - skipped++; - xfs_perag_put(pag); - continue; - } - first_index = pag->pag_ici_reclaim_cursor; - } else - mutex_lock(&pag->pag_ici_reclaim_lock); + /* + * If the cursor is not zero, we haven't scanned the whole AG + * so we might have skipped inodes here. + */ + first_index = READ_ONCE(pag->pag_ici_reclaim_cursor); + if (first_index) + skipped++; do { struct xfs_inode *batch[XFS_LOOKUP_BATCH]; @@ -1298,11 +1293,9 @@ xfs_reclaim_inodes_ag( } while (nr_found && !done && *nr_to_scan > 0); - if (trylock && !done) - pag->pag_ici_reclaim_cursor = first_index; - else - pag->pag_ici_reclaim_cursor = 0; - mutex_unlock(&pag->pag_ici_reclaim_lock); + if (done) + first_index = 0; + WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index); xfs_perag_put(pag); } return skipped; diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index d5dcf98698600..03158b42a1943 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -148,7 +148,6 @@ xfs_free_perag( ASSERT(atomic_read(&pag->pag_ref) == 0); xfs_iunlink_destroy(pag); xfs_buf_hash_destroy(pag); - mutex_destroy(&pag->pag_ici_reclaim_lock); call_rcu(&pag->rcu_head, __xfs_free_perag); } } @@ -200,7 +199,6 @@ xfs_initialize_perag( pag->pag_agno = index; pag->pag_mount = mp; spin_lock_init(&pag->pag_ici_lock); - mutex_init(&pag->pag_ici_reclaim_lock); INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC); if (xfs_buf_hash_init(pag)) goto out_free_pag; @@ -242,7 +240,6 @@ xfs_initialize_perag( out_hash_destroy: xfs_buf_hash_destroy(pag); out_free_pag: - mutex_destroy(&pag->pag_ici_reclaim_lock); kmem_free(pag); out_unwind_new_pags: /* unwind any prior newly initialized pags */ @@ -252,7 +249,6 @@ xfs_initialize_perag( break; xfs_buf_hash_destroy(pag); xfs_iunlink_destroy(pag); - mutex_destroy(&pag->pag_ici_reclaim_lock); kmem_free(pag); } return error; diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index 3725d25ad97e8..a72cfcaa4ad12 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -354,7 +354,6 @@ typedef struct xfs_perag { spinlock_t pag_ici_lock; /* incore inode cache lock */ struct radix_tree_root pag_ici_root; /* incore inode cache root */ int pag_ici_reclaimable; /* reclaimable inodes */ - struct mutex pag_ici_reclaim_lock; /* serialisation point */ unsigned long pag_ici_reclaim_cursor; /* reclaim restart point */ /* buffer cache index */