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 770AAC433EF for ; Sun, 19 Jun 2022 08:15:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234766AbiFSIPo (ORCPT ); Sun, 19 Jun 2022 04:15:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231437AbiFSIPk (ORCPT ); Sun, 19 Jun 2022 04:15:40 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB466E036 for ; Sun, 19 Jun 2022 01:15:39 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1655626537; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ozKBpCxlc961tRoJYmZ9NNhV2JVRg4NLegnLO9GahaU=; b=ZV89nUrNMAAbCeTJvDQkH6C/WptgNIESkT/FkozD0pJDaDohYwx4M5h4MkWB4jQf8pfAxR ZCm3LZjk45cmVGD3XA3XCzBxwQp5lI0b+WME+Hi7EvJ93vSi3r1cojBQCZ3f7QsomGBz8J h5tFj2MEn/4yQaG7MMbkP32vv8Hrts4f9epeKXQkeN/fzWdrjCa6iJFsYlgLMeYuzJNj2h u7nJAFNvofpFoZ+6QR7YrZMgBUMM1Voz1p4rxnhkT3N4XG5EA1Cnov+tvGduQfj0Tz6oyd lgOlFCoLqbfMWnSvCFA8B2M9RFNxbpWUg6ThqlwegvxvfXZufQLuLlA6eA7g7Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1655626537; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ozKBpCxlc961tRoJYmZ9NNhV2JVRg4NLegnLO9GahaU=; b=XkkUUc83Akog3zhpHcrLAcVJO1hEzToYOqdXAnAx7y4aOy56jzbwnmp3iCs0UTMTaWj0tZ P4+DxT01DjOsLiAQ== To: David Laight , 'Petr Mladek' , "Jason A. Donenfeld" Cc: Marco Elver , "linux-kernel@vger.kernel.org" Subject: RE: 5.19 printk breaks message ordering In-Reply-To: References: Date: Sun, 19 Jun 2022 10:21:37 +0206 Message-ID: <87edzlrrva.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-06-17, David Laight wrote: > What priority do these kthreads run at? 120 (SCHED_OTHER, nice=0) > I'd have thought they ought to run at a high priority? > That should tend to give kernel messages priority over user ones. > > Quite how high is another matter. > Probably a bit below the RT/FIFO:50 of threaded ISR. As a default value, I recommend keeping to the SCHED_OTHER policy as a default. Perhaps a nice value of -20? There are quite a few kernel threads using that as their default: # ps -Leo ni,command | grep ^-20 | sort -20 [acpi_thermal_pm] -20 [ata_sff] -20 [blkcg_punt_bio] -20 [cfg80211] -20 [inet_frag_wq] -20 [ipv6_addrconf] -20 [kblockd] -20 [kworker/0:0H-events_highpri] -20 [kworker/0:1H-events_highpri] -20 [md] -20 [mld] -20 [mm_percpu_wq] -20 [netns] -20 [nfsiod] -20 [rcu_gp] -20 [rcu_par_gp] -20 [rpciod] -20 [scsi_tmf_0] -20 [scsi_tmf_1] -20 [writeback] -20 [xprtiod] John Ogness