From: Eric Sandeen Subject: [PATCH] e2fsprogs: don't set stripe/stride to 1 block in mkfs Date: Mon, 04 Apr 2011 15:11:52 -0400 Message-ID: <4D9A17F8.4000406@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Zeev Tarantov To: ext4 development Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47812 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754682Ab1DDTLy (ORCPT ); Mon, 4 Apr 2011 15:11:54 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: Block devices may set minimum or optimal IO hints equal to blocksize; in this case there is really nothing for ext4 to do with this information (i.e. search for a block-aligned allocation?) so don't set fs geometry with single-block values. Zeev also reported that with a block-sized stripe, the ext4 allocator spends time spinning in ext4_mb_scan_aligned(), oddly enough. Reported-by: Zeev Tarantov Signed-off-by: Eric Sandeen --- diff --git a/misc/mke2fs.c b/misc/mke2fs.c index 9798b88..74b838c 100644 --- a/misc/mke2fs.c +++ b/misc/mke2fs.c @@ -1135,8 +1135,11 @@ static int get_device_geometry(const char *file, if ((opt_io == 0) && (psector_size > blocksize)) opt_io = psector_size; - fs_param->s_raid_stride = min_io / blocksize; - fs_param->s_raid_stripe_width = opt_io / blocksize; + /* setting stripe/stride to blocksize is pointless */ + if (min_io > blocksize) + fs_param->s_raid_stride = min_io / blocksize; + if (opt_io > blocksize) + fs_param->s_raid_stripe_width = opt_io / blocksize; rc = blkid_topology_get_alignment_offset(tp); out: