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 456A0C433EF for ; Thu, 25 Nov 2021 01:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348401AbhKYBuV (ORCPT ); Wed, 24 Nov 2021 20:50:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350221AbhKYBsP (ORCPT ); Wed, 24 Nov 2021 20:48:15 -0500 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88ABCC07E5C2 for ; Wed, 24 Nov 2021 16:53:55 -0800 (PST) Received: by mail-pl1-x62c.google.com with SMTP id u11so3256119plf.3 for ; Wed, 24 Nov 2021 16:53:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=scJBclGIopOVvG3HSUpsjPmCQQn013b/K/39DlZv3x4=; b=ScoHsauE0NTyr0yybyYp1l2UwStVFF1tAnpH5fnJhEkea+UGTrOHxRtGfqirT8Ya8D DTvx2TtIeKGlEd+BtCbgLDOR5BE3veGp/R6TmMw9pvs9iLNFY+xcNyuAO2pKzwxFuMWB wGVRboyX8VzPtGkMASZqTCV9dWUSfx3bIBxRM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=scJBclGIopOVvG3HSUpsjPmCQQn013b/K/39DlZv3x4=; b=gw3fcv3i6mVIms0ZzxVQfRJxOethfMPt1Ku0QA0Vl41Yf6fCzGRZ3CWuWt689cJqnP qltMH5Oevx0PmZffkLWGW/ou4Rrx7GpqQmPlSk2do2/0OUXhvBNLUh9BjdxNm+jBFovr Bfh/rQ9om3216A/+60nVdUIsF8hag07G6qXnEM8WgSRw/j5HFNPzfuvtc//ksNOHqTeA xu94gXhxk0E7M9CdqopN+1voUSGAfWkxTITikhZr9Id68ViHZDv+mVbOyffuj6Ztg0ou XCDPFuKRG1XJbDHGQ9zg7GF6dupHI7s0x4mnqk7q4FTthoQk9GzX+/qcyknSVgKCiD3A 8/OQ== X-Gm-Message-State: AOAM532NmhgtqgxXusIQ7v7wmYCCVvza/qOU7Nlb9cmouWTj00ohLZbs umvLnWOI0s5wslEv3UNCIj30Sg== X-Google-Smtp-Source: ABdhPJzyHEzyR7ArhBFbwqnc3bmS+Tf811bPK8hZDgLgPfudi/aPrXj1HmSLYypSmW5O1lH6o4JzwQ== X-Received: by 2002:a17:903:2344:b0:142:25b4:76c1 with SMTP id c4-20020a170903234400b0014225b476c1mr25324384plh.43.1637801634938; Wed, 24 Nov 2021 16:53:54 -0800 (PST) Received: from google.com ([240f:75:7537:3187:5469:38f8:3785:7433]) by smtp.gmail.com with ESMTPSA id ml24sm768144pjb.16.2021.11.24.16.53.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Nov 2021 16:53:54 -0800 (PST) Date: Thu, 25 Nov 2021 09:53:49 +0900 From: Sergey Senozhatsky To: Petr Mladek Cc: John Ogness , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Joe Perches , linux-kernel@vger.kernel.org Subject: Re: [RFC] printk: More consistent loglevel for continuous lines Message-ID: References: <20211124154838.5415-1-pmladek@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211124154838.5415-1-pmladek@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (21/11/24 16:48), Petr Mladek wrote: > > Anyway, it looks a bit non-practical to update all existing pr_cont() > callers: > > $> git grep "pr_cont" | wc -l > 2054 Another question is how many pr_cont()-s are getting compiled with the "average" production kernel config. A number of pr_cont() is in debugging code - lockdep, kasan, etc. - which is not compiled for prod. [..] > +static void printk_write_loglevel_ctx(int loglevel) > +{ > + u8 *loglevel_var = printk_loglevel_ctx_var(); > + > + if (!loglevel_var) > + return; > + > + /* > + * Remember only the really used loglevels that can be stored > + * within 3 bytes in struct printk_info. > + */ > + if (WARN_ON_ONCE(loglevel != LOG_LEVEL(loglevel))) > + return; > + > + *loglevel_var = loglevel; > +} > + > +static u8 printk_read_loglevel_ctx(void) > +{ > + u8 *loglevel_var = printk_loglevel_ctx_var(); > + > + if (!loglevel_var) > + return LOGLEVEL_DEFAULT; > + > + return *loglevel_var; > +} > + > /** > * printk_parse_prefix - Parse level and control flags. > * > @@ -2066,6 +2122,21 @@ u16 printk_parse_prefix(const char *text, int *level, > return prefix_len; > } > > +static int printk_sanitize_loglevel(int loglevel, enum printk_info_flags flags) > +{ > + /* For continuous lines, fallback to the previously used loglevel. */ > + if (flags & LOG_CONT && loglevel == LOGLEVEL_DEFAULT) > + loglevel = printk_read_loglevel_ctx(); > + > + if (loglevel == LOGLEVEL_DEFAULT) > + loglevel = default_message_loglevel; > + > + /* Remember the really used loglevel for this context. */ > + printk_write_loglevel_ctx(loglevel); > + > + return loglevel; > +} Let's assume something like this foo() { char *s; pr_cont("Blah "); s = arch_foo(); pr_cont("%s \n", s); } Suppose that arch_foo() errs and pr_warn()-s. Are we going to use WARN level for trailing pr_cont()? pr_cont("Blah ") -> printk_write_loglevel_ctx(default) pr_warn() -> printk_write_loglevel_ctx(warn) pr_cont("%s \n"") <- printk_read_loglevel_ctx(warn) p.s. I'm still reading amazingly detailed commit messages from your console registration patch set.