From owner-svn-src-head@FreeBSD.ORG Tue Jul 29 09:36:48 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B8E8BB8B; Tue, 29 Jul 2014 09:36:48 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8D53021D9; Tue, 29 Jul 2014 09:36:48 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s6T9amJN068438; Tue, 29 Jul 2014 09:36:48 GMT (envelope-from delphij@svn.freebsd.org) Received: (from delphij@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id s6T9amcr068437; Tue, 29 Jul 2014 09:36:48 GMT (envelope-from delphij@svn.freebsd.org) Message-Id: <201407290936.s6T9amcr068437@svn.freebsd.org> From: Xin LI Date: Tue, 29 Jul 2014 09:36:48 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r269230 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Jul 2014 09:36:48 -0000 Author: delphij Date: Tue Jul 29 09:36:48 2014 New Revision: 269230 URL: http://svnweb.freebsd.org/changeset/base/269230 Log: MFV r269224: Increase default ARC buf_hash_table size. When typical block size is small, the hash table could be too small, which would lead to long hash chains and limit performance for cached reads. A new loader tunable, vfs.zfs.arc_average_blocksize, have been added which allows users to override the default assumption of average (typical) block size. Old default was 65536 (64 KiB) and new default is 8192 (8 KiB). Illumos issue: 5034 ARC's buf_hash_table is too small MFC after: 2 weeks Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Directory Properties: head/sys/cddl/contrib/opensolaris/ (props changed) Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Tue Jul 29 08:42:22 2014 (r269229) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Tue Jul 29 09:36:48 2014 (r269230) @@ -203,6 +203,7 @@ int zfs_arc_grow_retry = 0; int zfs_arc_shrink_shift = 0; int zfs_arc_p_min_shift = 0; int zfs_disable_dup_eviction = 0; +uint64_t zfs_arc_average_blocksize = 8 * 1024; /* 8KB */ TUNABLE_QUAD("vfs.zfs.arc_meta_limit", &zfs_arc_meta_limit); SYSCTL_DECL(_vfs_zfs); @@ -210,6 +211,9 @@ SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_max "Maximum ARC size"); SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_min, CTLFLAG_RDTUN, &zfs_arc_min, 0, "Minimum ARC size"); +SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_average_blocksize, CTLFLAG_RDTUN, + &zfs_arc_average_blocksize, 0, + "ARC average blocksize"); /* * Note that buffers can be in one of 6 states: @@ -1054,10 +1058,11 @@ buf_init(void) /* * The hash table is big enough to fill all of physical memory - * with an average 64K block size. The table will take up - * totalmem*sizeof(void*)/64K (eg. 128KB/GB with 8-byte pointers). + * with an average block size of zfs_arc_average_blocksize (default 8K). + * By default, the table will take up + * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers). */ - while (hsize * 65536 < (uint64_t)physmem * PAGESIZE) + while (hsize * zfs_arc_average_blocksize < (uint64_t)physmem * PAGESIZE) hsize <<= 1; retry: buf_hash_table.ht_mask = hsize - 1;