From patchwork Fri Mar 1 16:42:25 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Sandeen X-Patchwork-Id: 224407 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 132BF2C007E for ; Sat, 2 Mar 2013 03:42:52 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752218Ab3CAQmd (ORCPT ); Fri, 1 Mar 2013 11:42:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:8112 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751197Ab3CAQmb (ORCPT ); Fri, 1 Mar 2013 11:42:31 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r21GgR0b007654 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 1 Mar 2013 11:42:27 -0500 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r21GgPTQ028974 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Fri, 1 Mar 2013 11:42:26 -0500 Message-ID: <5130DA71.4040808@redhat.com> Date: Fri, 01 Mar 2013 10:42:25 -0600 From: Eric Sandeen User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130216 Thunderbird/17.0.3 MIME-Version: 1.0 To: "Theodore Ts'o" CC: Dave Jones , "gnehzuil.liu" , Zheng Liu , "linux-ext4@vger.kernel.org" Subject: [PATCH] ext4: use percpu counter for extent cache count References: <7BFB2135-A1F0-4B6D-9962-16E75E5560F8@gmail.com> <20130227174553.GA224@x4> <20130227184912.GA19624@thunk.org> <20130227185625.GA224@x4> <20130227191923.GA1121@redhat.com> <20130227192907.GB14253@thunk.org> <20130227201217.GD14253@thunk.org> <20130301033005.GA7081@redhat.com> <20130301040039.GA4452@thunk.org> <20130301050029.GB4452@thunk.org> In-Reply-To: <20130301050029.GB4452@thunk.org> X-Enigmail-Version: 1.5 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Use a percpu counter rather than atomic types for shrinker accounting. There's no need for ultimate accuracy in the shrinker, so this should come a little more cheaply. The percpu struct is somewhat large, but there was a big gap before the cache-aligned s_es_lru_lock anyway, and it fits nicely in there. Signed-off-by: Eric Sandeen --- -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 96c1093..4a01ba3 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1268,7 +1268,6 @@ struct ext4_sb_info { atomic_t s_mb_preallocated; atomic_t s_mb_discarded; atomic_t s_lock_busy; - atomic_t s_extent_cache_cnt; /* locality groups */ struct ext4_locality_group __percpu *s_locality_groups; @@ -1310,6 +1309,7 @@ struct ext4_sb_info { /* Reclaim extents from extent status tree */ struct shrinker s_es_shrinker; struct list_head s_es_lru; + struct percpu_counter s_extent_cache_cnt; spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp; }; diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 27fcdd2..95796a1 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -305,7 +305,7 @@ ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len, */ if (!ext4_es_is_delayed(es)) { EXT4_I(inode)->i_es_lru_nr++; - atomic_inc(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt); + percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt); } return es; @@ -317,7 +317,7 @@ static void ext4_es_free_extent(struct inode *inode, struct extent_status *es) if (!ext4_es_is_delayed(es)) { BUG_ON(EXT4_I(inode)->i_es_lru_nr == 0); EXT4_I(inode)->i_es_lru_nr--; - atomic_dec(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt); + percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt); } kmem_cache_free(ext4_es_cachep, es); @@ -678,7 +678,7 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc) int nr_to_scan = sc->nr_to_scan; int ret, nr_shrunk = 0; - ret = atomic_read(&sbi->s_extent_cache_cnt); + ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt); trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret); if (!nr_to_scan) @@ -711,7 +711,7 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc) list_splice_tail(&scanned, &sbi->s_es_lru); spin_unlock(&sbi->s_es_lru_lock); - ret = atomic_read(&sbi->s_extent_cache_cnt); + ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt); trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret); return ret; }