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 28834C433F5 for ; Wed, 2 Mar 2022 09:24:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9E8EC8D0002; Wed, 2 Mar 2022 04:24:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 999318D0001; Wed, 2 Mar 2022 04:24:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 887C08D0002; Wed, 2 Mar 2022 04:24:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0181.hostedemail.com [216.40.44.181]) by kanga.kvack.org (Postfix) with ESMTP id 762D18D0001 for ; Wed, 2 Mar 2022 04:24:18 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2CF0818099ADD for ; Wed, 2 Mar 2022 09:24:18 +0000 (UTC) X-FDA: 79198910196.25.0F22EBD Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf30.hostedemail.com (Postfix) with ESMTP id 8E4828000A for ; Wed, 2 Mar 2022 09:24:17 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 696FD1F39D; Wed, 2 Mar 2022 09:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1646213056; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=clM0yYlLqEX7Y5ui9U1ErugOMUrW/ceVhGC6xR2tAew=; b=GxV9t9jA8UzFp10mgfTYqscDn3mqAyjQkUDkNOZ6WudDgkD7fZ24C2xIm1J1lwjPWv5Hqx KAwG4h+6/IKc3x4mcMJTcacF5wckqSBifZjASvkwxdtNedohTlXsBSH6VACa8L07DZFfwg JNMv0pJ3iN3bsv52RjAy+hn8LSMzPpg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1646213056; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=clM0yYlLqEX7Y5ui9U1ErugOMUrW/ceVhGC6xR2tAew=; b=//kv8L4NT9j55yEeAww5drvSB7x88AZTHCxd6ugQ9HVtKzCBWy2rLFVIP1Y5dDzFAPITnN yxItsAQPEssSgTCg== Received: from quack3.suse.cz (unknown [10.100.200.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 48383A3B87; Wed, 2 Mar 2022 09:24:16 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id EBD45A0608; Wed, 2 Mar 2022 10:24:15 +0100 (CET) Date: Wed, 2 Mar 2022 10:24:15 +0100 From: Jan Kara To: Richard Weinberger Cc: Jan Kara , wuchi zero , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , tj , mszeredi , sedat dilek , axboe , Andrew Morton , torvalds , linux-mm , linux-mtd , linux-fsdevel , linux-kernel Subject: Re: Different writeback timing since v5.14 Message-ID: <20220302092415.4sikhzup7sorhxgy@quack3.lan> References: <2104629126.100059.1646129517209.JavaMail.zimbra@nod.at> <20220301103218.ulbmakdy4gbw2fso@quack3.lan> <719960584.100772.1646147154879.JavaMail.zimbra@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <719960584.100772.1646147154879.JavaMail.zimbra@nod.at> X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 8E4828000A X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=GxV9t9jA; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="//kv8L4N"; dmarc=none; spf=pass (imf30.hostedemail.com: domain of jack@suse.cz designates 195.135.220.29 as permitted sender) smtp.mailfrom=jack@suse.cz X-Stat-Signature: 566h71xx7pm9kqbmnknzxedu88di1ne8 X-HE-Tag: 1646213057-65417 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 01-03-22 16:05:54, Richard Weinberger wrote: > Jan, >=20 > ----- Urspr=FCngliche Mail ----- > > Von: "Jan Kara" > >> Is this expected? > >> Just want to make sure that the said commit didn't uncover an UBIFS = issue. > >=20 > > Yes, I think it is expected. Likely the background threshold for UBIF= S bdi > > is very small (probably UBIFS is not used much for writeback compared= to > > other filesystems). Previously, we just used wb_stat() which returned= 0 > > (PCP counter inexact value) and so background writeback didn't trigge= r. Now > > we use wb_stat_sum() when threshold is small, get exact value of dirt= y > > pages and decide to start background writeback. >=20 > Thanks for the prompt reply! >=20 > > The only thing is, whether it is really expected that the threshold f= or > > UBIFS bdi is so small. You can check the values in > > /sys/kernel/debug/bdi//stats. >=20 > BdiDirtyThresh is indeed 0. >=20 > BdiWriteback: 0 kB > BdiReclaimable: 0 kB > BdiDirtyThresh: 0 kB > DirtyThresh: 772620 kB > BackgroundThresh: 385836 kB > BdiDirtied: 0 kB > BdiWritten: 0 kB > BdiWriteBandwidth: 102400 kBps > b_dirty: 0 > b_io: 0 > b_more_io: 0 > b_dirty_time: 0 > bdi_list: 1 > state: 1 Yes, so this looks expected given the BDI wasn't active yet at all... Honza --=20 Jan Kara SUSE Labs, CR