From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:46950 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482AbaJFJbw (ORCPT ); Mon, 6 Oct 2014 05:31:52 -0400 Message-ID: <5432617B.8050301@oracle.com> Date: Mon, 06 Oct 2014 17:31:39 +0800 From: Anand Jain MIME-Version: 1.0 To: dsterba@suse.cz, linux-btrfs@vger.kernel.org, guihc.fnst@cn.fujitsu.com, sandeen@redhat.com Subject: Re: [PATCH 1/5] btrfs-progs: scan /proc/partitions not all of /dev with "-d" References: <1410571282-3482-1-git-send-email-anand.jain@oracle.com> <20140923170002.GX9715@twin.jikos.cz> In-Reply-To: <20140923170002.GX9715@twin.jikos.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: I am running some tests with larger disks pool (48 disks). With that the performance of the various scan methods are as below.. ---- scanning BTRFS_SCAN_LBLKID real 0m0.330s user 0m0.005s sys 0m0.026s scanning BTRFS_SCAN_DEV real 0m0.010s user 0m0.002s sys 0m0.005s scanning BTRFS_SCAN_PROC real 0m0.010s user 0m0.002s sys 0m0.005s ----- This is the time taken to scan 48disks one time by various methods we have/had - but our progs do this scan 30times for btrfs fi show. yep 30times as show below.. I am working to fix it. ------- Function: time(us) count avg(us) :: get_device_info: 1034 27 38 pretty_size_snprintf: 1218 124 9 btrfs_scan_one_device: 1790 186 9 btrfs_read_dev_super: 1956 116 16 cmd_show: 15418 335 46 btrfs_scan_lblkid: 148477 30 4949 ------- IMO we should still stick to LBLKID scan. Just a thought - any idea if its better to provide a compile time fallback scan switch, just in case if something fails with lblkid. ? Thanks, Anand On 09/24/14 01:00, David Sterba wrote: > Hi, > > all 5 patches will be in the next integration. I haven't tested them > yet, seems it's a bit more important to make a more stable devel base > for more updates you might want to send. > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >