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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 518F7C433EF for ; Tue, 1 Mar 2022 10:12:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B71C28D0002; Tue, 1 Mar 2022 05:12:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B21528D0001; Tue, 1 Mar 2022 05:12:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A100B8D0002; Tue, 1 Mar 2022 05:12:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 911558D0001 for ; Tue, 1 Mar 2022 05:12:00 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 5071061583 for ; Tue, 1 Mar 2022 10:12:00 +0000 (UTC) X-FDA: 79195401600.11.D96E522 Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by imf09.hostedemail.com (Postfix) with ESMTP id 9390E14000D for ; Tue, 1 Mar 2022 10:11:59 +0000 (UTC) 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: quoted-printable 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 X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 9390E14000D X-Stat-Signature: 16t6o5qr3c3ywagidojpw418cmo8ayk6 Authentication-Results: imf09.hostedemail.com; dkim=none; spf=pass (imf09.hostedemail.com: domain of richard@nod.at designates 195.201.40.130 as permitted sender) smtp.mailfrom=richard@nod.at; dmarc=none X-HE-Tag: 1646129519-404857 X-Bogosity: Ham, tests=bogofilter, spamicity=0.027201, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi! Rafa=C5=82 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 t= akes 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