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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 1AD37C4338F for ; Mon, 9 Aug 2021 07:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED07761002 for ; Mon, 9 Aug 2021 07:43:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233533AbhHIHng (ORCPT ); Mon, 9 Aug 2021 03:43:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233514AbhHIHnf (ORCPT ); Mon, 9 Aug 2021 03:43:35 -0400 X-Greylist: delayed 34202 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 09 Aug 2021 00:43:15 PDT Received: from mail.valdk.tel (mail.valdk.tel [IPv6:2a02:e00:ffe7:c::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27288C061796 for ; Mon, 9 Aug 2021 00:43:14 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id D1F3E24D08F; Mon, 9 Aug 2021 10:43:09 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=valdikss.org.ru; s=msrv; t=1628494990; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=j/HDCveL7/s6PO3Cojbm2xxwwRkp04B45qsFfM5gedA=; b=O+8EK/k+ZmGf1oYSlizBNDLceOS+18BXHDN80DW6t+A3TqoNT7ZTnf/423AjYAUWTxnFnB gO6MmJ4vXfjMifqf4lSTqzFXtM+W9ciRbDuq4nMzqnouJomU6SwwVAuKG506GX2pmlHWbg Oo/Al3/aD44Il0IwjTuQ0fBNgM1gSNB9fWZYVzShiDypItVO9nxr0235nMg0P6ZvWH4nuy DkpWLXjgqcBlJG1h/8Ele7+dgb30U3MpB+HezLOuZAp10m6I/CfKZ95p88EhUeaFHFvceV bjfiehm0Ye5gfGrhhh9IkkeP0lQqN/woAtHZCW9AF3T0YZArWXxET3qvYaasKw== To: Theodore Ts'o Cc: linux-ext4@vger.kernel.org References: <015c7506-7f33-3967-772a-1285b0f1052f@valdikss.org.ru> From: ValdikSS Subject: Re: ext4lazyinit reads HDD data on mount since 5.13 Message-ID: Date: Mon, 9 Aug 2021 10:43:08 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.5.0) Gecko/20100101, Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On 09.08.2021 04:51, Theodore Ts'o wrote: > It's a new feature which optimizes block allocations for very large > file systems. The work being done by ext4lazyinit is to read the > block allocation bitmaps so we can cache the buddy bitmaps and how > fragmented (or not) various block groups are, which is used to > optimize the block allocator. Thanks for the info. To revert old behavior, the filesystem should be mounted with -o no_prefetch_block_bitmaps Is it safe to use this option with new optimizations? Should I expect only less optimal filesystem speed and no other issues?