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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 293D8C4338F for ; Tue, 17 Aug 2021 00:16:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F38A060F55 for ; Tue, 17 Aug 2021 00:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234314AbhHQARB (ORCPT ); Mon, 16 Aug 2021 20:17:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:53708 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232903AbhHQAQ6 (ORCPT ); Mon, 16 Aug 2021 20:16:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8A97B60F39; Tue, 17 Aug 2021 00:16:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629159385; bh=KG4aBz3LsYlQoj4ZmeJ8bEqC+SJgiUisze7eXuaacNw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FH21FE+LDI3lyirYFQijw7ZRz0nDvutSJqqu4l7oDJW0uI5WqA0yzgFjJMbKUGf/R l2FmB9sYbVeuC8J0cBjwDOjmK3haT9rq+8hUDnNdKUizhmoMNufsWg3rkoTVwRIzk3 3AnVZVR4inSti0ydlAddPzmoE/2tBuKWCC1+8HyMHjZP26suketwsTBdXJ87PhEDZY WaoWbGtUBUDcckPN+zD1qzg1zqoBeEAjSxAcKoGYx6f0WXDKclYTyZOyXShsah2d9g Zx/TjFr5FBhNsXHq2jOA4/9oIig53WsOYpd81YFqSL7j7hNpXhKf8hTEBY1Hzvd9WC MbBqKVIQs5SJQ== Date: Mon, 16 Aug 2021 17:16:24 -0700 From: Jaegeuk Kim To: =?utf-8?B?5p2O5oms6Z+s?= Cc: Chao Yu , linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] f2fs: add sysfs nodes to get discard information Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/16, 李扬韬 wrote: > >>>> I've added new sysfs nodes to show discard stat since mount, which > >>>> will help us analyze whether the performance problem is related to > >>>> discard. > >>>> > >>>> issued_discard - Shows the number of issued discard > >>>> queued_discard - Shows the number of cached discard cmd count > >>>> discard_cmd_cnt - Shows the number of cached discard cmd count > >>>> undiscard_blks - Shows the number of undiscard blocks > >>> > >>> We have exported them in debugfs, can you use that? > >>> > >>> Thanks, > >> > >> But now Android is forbidden to open debugfs, and in fact we have not > >> opened this configuration for a long time. > > > >Weren't them be used for debug purpose? can you please explain more about > >your use case? > > During long-term aging test or normal use, sometimes there will be performance > degradation problems. It may be caused by storage, or it may be caused by the > filesystem. For example, the filesystem accumulates a large number of undiscard > blocks. Although there is some remaining space, the androidbench test will > show performance degradation. Therefore, it is necessary to export information > related to discard so that we can confirm this situation. I think you can mount debugfs for that case? > > Thx, > >