From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71C95C070C3 for ; Mon, 15 Oct 2018 02:32:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0097620659 for ; Mon, 15 Oct 2018 02:32:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0097620659 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cn.fujitsu.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbeJOKPr (ORCPT ); Mon, 15 Oct 2018 06:15:47 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:53268 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726098AbeJOKPq (ORCPT ); Mon, 15 Oct 2018 06:15:46 -0400 X-IronPort-AV: E=Sophos;i="5.43,368,1503331200"; d="scan'208";a="46134292" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 15 Oct 2018 10:32:36 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 67C6A4B6ED5F; Mon, 15 Oct 2018 10:32:33 +0800 (CST) Received: from fnst.localdomain (10.167.226.155) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 15 Oct 2018 10:32:37 +0800 Date: Mon, 15 Oct 2018 10:32:30 +0800 From: Lu Fengqi To: , Nikolay Borisov , Subject: Re: [PATCH 5/6] btrfs: simplify btrfs_select_ref_head and cleanup some local variables Message-ID: <20181015023230.GE3369@fnst.localdomain> References: <20181011054038.5428-1-lufq.fnst@cn.fujitsu.com> <20181011054038.5428-6-lufq.fnst@cn.fujitsu.com> <20181011121558.GF5899@fnst.localdomain> <0b78a3dc-bf22-fb99-afce-96b74d936173@suse.com> <20181011124504.GQ29418@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20181011124504.GQ29418@twin.jikos.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-Originating-IP: [10.167.226.155] X-yoursite-MailScanner-ID: 67C6A4B6ED5F.AF439 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: lufq.fnst@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Oct 11, 2018 at 02:45:04PM +0200, David Sterba wrote: >On Thu, Oct 11, 2018 at 03:28:15PM +0300, Nikolay Borisov wrote: >> > I noticed that there is a macro called SCRAMBLE_DELAYED_REFS in the >> > extent-tree.c. I am a bit curious whether it has been forgotten by >> > everyone, I have not found any test results about its performance impact. >> >> I guess it was used during testing but nothing currently sets it. I.e it >> might make sense to enable it if BTRFS_DEBUG is set. > >Agreed, the way the scrambling is supposed to be used does not align >very well with the typical testing workflow so adding to ti the >BTRFS_DEBUG set is ok, unless there are severe performance problems. I will add it to the BTRFS_DEBUG set, and test if it has severe performance problems. > >The part in btrfs_run_delayed_refs would be better hidden in a function >similar to btrfs_debug_check_extent_io_range or btrfs_leak_debug_check. Got it. -- Thanks, Lu