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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4311AC433F5 for ; Tue, 1 Mar 2022 10:28:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233863AbiCAK3A convert rfc822-to-8bit (ORCPT ); Tue, 1 Mar 2022 05:29:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230272AbiCAK26 (ORCPT ); Tue, 1 Mar 2022 05:28:58 -0500 X-Greylist: delayed 600 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 01 Mar 2022 02:28:16 PST Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E03E4F9F5; Tue, 1 Mar 2022 02:28:16 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id D7119609B3C0; Tue, 1 Mar 2022 11:11:57 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id uHtvGrDw6G89; Tue, 1 Mar 2022 11:11:57 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 77E61609B3F0; Tue, 1 Mar 2022 11:11:57 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id V9Nv3lnaehro; Tue, 1 Mar 2022 11:11:57 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 47DDE609B3C0; Tue, 1 Mar 2022 11:11:57 +0100 (CET) Date: Tue, 1 Mar 2022 11:11:57 +0100 (CET) From: Richard Weinberger To: wuchi.zero@gmail.com Cc: =?utf-8?Q?Rafa=C5=82_Mi=C5=82ecki?= , jack@suse.cz, tj@kernel.org, mszeredi@redhat.com, sedat.dilek@gmail.com, axboe@fb.com, akpm@linux-foundation.org, torvalds@linux-foundation.org, linux-mm , linux-mtd , linux-fsdevel , linux-kernel Message-ID: <2104629126.100059.1646129517209.JavaMail.zimbra@nod.at> Subject: Different writeback timing since v5.14 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF97 (Linux)/8.8.12_GA_3809) Thread-Index: 5JNzjBL9+smBCCGCkEapAfbWm9hEtw== Thread-Topic: Different writeback timing since v5.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! Rafał and I discovered that page writeback on UBIFS behaves different since v5.14. When a simple write, such as "echo foo > /mnt/ubibfs/bar.txt", happens it takes a few seconds until writeback calls ubifs_writepage(). Before commit ab19939a6a50 ("mm/page-writeback: Fix performance when BDI's share of ratio is 0.") it was 30 seconds (vm.dirty_expire_centisecs), after this change it happens after 5 seconds (vm.dirty_writeback_centisecs). Is this expected? Just want to make sure that the said commit didn't uncover an UBIFS issue. Thanks, //richard