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 1F91DC4332F for ; Mon, 21 Nov 2022 16:09:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230419AbiKUQJb (ORCPT ); Mon, 21 Nov 2022 11:09:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229831AbiKUQJ1 (ORCPT ); Mon, 21 Nov 2022 11:09:27 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F8CBCEB8B; Mon, 21 Nov 2022 08:09:26 -0800 (PST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 34E261F899; Mon, 21 Nov 2022 16:09:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1669046965; 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=IpvY7HmeSZqqsYSrW2HTvY/yDZgDDPGYw0H4l9bmBk0=; b=aZ2RB9Em01NnaniZqFFQvHgiRuAREy3Fd7QAPriQJglGYZsLdQUER8B7BPvQg0B/SPVzvo VU2mz1GHvs6BBHTea+ETmRPmP8Metgs+lhN8fRghQsPVbjpMWynhvYri16+PBqXuFxyezX aWd6dKixOABM4Yrr7DLfPgIUQHKAL4E= Received: from suse.cz (unknown [10.100.201.202]) (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 0E1D32C146; Mon, 21 Nov 2022 16:09:25 +0000 (UTC) Date: Mon, 21 Nov 2022 17:09:21 +0100 From: Petr Mladek To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: "Rafael J. Wysocki" , Pavel Machek , Len Brown , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] power: process: use explicit levels for printk continuations Message-ID: References: <20221121050946.3540-1-linux@weissschuh.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20221121050946.3540-1-linux@weissschuh.net> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon 2022-11-21 06:09:46, Thomas Weißschuh wrote: > Many of the printk messages emitted during suspend and resume are > emitted in fragments using pr_cont()/KERN_CONT. > > As during suspend and resume a lot of operations are happing in the > kernel the chances are high that the fragments are interspersed with > unrelated messages. > > In this case if no explicit level is specified for the fragments the > standard level is applied, which by default is KERN_WARNING. > > If the user is only observing KERN_WARNING and *not* KERN_INFO messages > they will see incomplete message fragments. > > By specifing the correct printk level also with the continuations this > mismatch can be avoided. > Also it reduces the amount of false-positive KERN_WARNING messages. Yup, it is a known printk() limitation and this is the most reliable solution. > Signed-off-by: Thomas Weißschuh > --- > kernel/power/process.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/kernel/power/process.c b/kernel/power/process.c > index ddd9988327fe..0a828edc6d30 100644 > --- a/kernel/power/process.c > +++ b/kernel/power/process.c > @@ -101,7 +101,7 @@ static int try_to_freeze_tasks(bool user_only) > read_unlock(&tasklist_lock); > } > } else { > - pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000, > + pr_info(KERN_CONT "(elapsed %d.%03d seconds) ", elapsed_msecs / 1000, It looks a bit ugly. Feel free to provide separate patch introducing pr__cont() wrappers. Then you could use pr_info_cont() here. We already have pr__once() and pr__ratelimited(). So pr__cont() would fit the existing pattern. > elapsed_msecs % 1000); > } > Best Regards, Petr