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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D786DC433DF for ; Wed, 27 May 2020 09:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFF9D20890 for ; Wed, 27 May 2020 09:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725910AbgE0JcG (ORCPT ); Wed, 27 May 2020 05:32:06 -0400 Received: from mail.thelounge.net ([91.118.73.15]:52799 "EHLO mail.thelounge.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725882AbgE0JcF (ORCPT ); Wed, 27 May 2020 05:32:05 -0400 Received: from srv-rhsoft.rhsoft.net (rh.vpn.thelounge.net [10.10.10.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) (Authenticated sender: h.reindl@thelounge.net) by mail.thelounge.net (THELOUNGE MTA) with ESMTPSA id 49X5FZ3DSLzXSL; Wed, 27 May 2020 11:32:02 +0200 (CEST) Subject: Re: [PATCH] ext4: introduce EXT4_BG_WAS_TRIMMED to optimize trim To: Lukas Czerner , Wang Shilong Cc: linux-ext4@vger.kernel.org, Wang Shilong , Shuichi Ihara , Andreas Dilger References: <1590565130-23773-1-git-send-email-wangshilong1991@gmail.com> <20200527091938.647363ekmnz7av7y@work> From: Reindl Harald Organization: the lounge interactive design Message-ID: <520b260b-13e9-4c62-eaeb-c44215b14089@thelounge.net> Date: Wed, 27 May 2020 11:32:02 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200527091938.647363ekmnz7av7y@work> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Am 27.05.20 um 11:19 schrieb Lukas Czerner: > On Wed, May 27, 2020 at 04:38:50PM +0900, Wang Shilong wrote: >> From: Wang Shilong >> >> Currently WAS_TRIMMED flag is not persistent, whenever filesystem was >> remounted, fstrim need walk all block groups again, the problem with >> this is FSTRIM could be slow on very large LUN SSD based filesystem. >> >> To avoid this kind of problem, we introduce a block group flag >> EXT4_BG_WAS_TRIMMED, the side effect of this is we need introduce >> extra one block group dirty write after trimming block group. would that also fix the issue that *way too much* is trimmed all the time, no matter if it's a thin provisioned vmware disk or a phyiscal RAID10 with SSD no way of 315 MB deletes within 2 hours or so on a system with just 485M used [root@firewall:~]$ fstrim -av /boot: 0 B (0 bytes) trimmed on /dev/sda1 /: 315.2 MiB (330522624 bytes) trimmed on /dev/sdb1 [root@firewall:~]$ df Filesystem Type Size Used Avail Use% Mounted on /dev/sdb1 ext4 5.8G 463M 5.4G 8% / /dev/sda1 ext4 485M 42M 440M 9% /boot