Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 25 Nov 2022 21:33:40 +0100
From:   Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <linux@weissschuh.net>
To:     Joe Perches <joe@perches.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>,
        linux-pm@vger.kernel.org, Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Andy Whitcroft <apw@canonical.com>,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
        Dwaipayan Ray <dwaipayanray1@gmail.com>,
        Lukas Bulwahn <lukas.bulwahn@gmail.com>
Subject: Re: [PATCH v2 1/3] printk: introduce new macros pr_<level>_cont()
Message-ID: <cf45b62e-6248-42f3-807f-5df0954437e0@t-8ch.de>
References: <20221125190948.2062-1-linux@weissschuh.net>
 <20221125190948.2062-2-linux@weissschuh.net>
 <1fb146231e1810b4c9923f384afa166e07e7f253.camel@perches.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1fb146231e1810b4c9923f384afa166e07e7f253.camel@perches.com>
Jabber-ID: thomas@t-8ch.de
Precedence: bulk

On 2022-11-25 12:18-0800, Joe Perches wrote:
> On Fri, 2022-11-25 at 20:09 +0100, Thomas Weißschuh wrote:
>> These macros emit continuation messages with explicit levels.
>> In case the continuation is logged separately from the original message
>> it will retain its level instead of falling back to KERN_DEFAULT.
>> 
>> This remedies the issue that logs filtered by level contain stray
>> continuation messages without context.
>> 
>> Suggested-by: Petr Mladek <pmladek@suse.com>
>> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
>> ---
>>  include/linux/printk.h | 23 +++++++++++++++++++++++
>>  1 file changed, 23 insertions(+)
>> 
>> diff --git a/include/linux/printk.h b/include/linux/printk.h
>> index 8c81806c2e99..8f564c38f121 100644
>> --- a/include/linux/printk.h
>> +++ b/include/linux/printk.h
>> @@ -537,6 +537,8 @@ struct pi_entry {
>>   * This macro expands to a printk with KERN_CONT loglevel. It should only be
>>   * used when continuing a log message with no newline ('\n') enclosed. Otherwise
>>   * it defaults back to KERN_DEFAULT loglevel.
>> + *
>> + * Use the dedicated pr_<level>_cont() macros instead.
>>   */
>>  #define pr_cont(fmt, ...) \
>>  	printk(KERN_CONT fmt, ##__VA_ARGS__)
>> @@ -701,6 +703,27 @@ do {									\
>>  	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
>>  #endif
>>  
>> +/*
>> + * Print a continuation message with level. In case the continuation is split
>> + * from the main message it preserves the level.
>> + */
>> +
>> +#define pr_emerg_cont(fmt, ...)					\
>> +	printk(KERN_EMERG KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
> 
> Aren't this rather backwards?
> KERN_CONT KERN_<LEVEL> seems to make more sense to me.

If nobody else disagrees I'll do this for v3.

>> +#define pr_alert_cont(fmt, ...)					\
>> +	printk(KERN_ALERT KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +#define pr_crit_cont(fmt, ...)					\
>> +	printk(KERN_CRIT KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +#define pr_err_cont(fmt, ...)					\
>> +	printk(KERN_ERR KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +#define pr_warn_cont(fmt, ...)					\
>> +	printk(KERN_WARN KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +#define pr_notice_cont(fmt, ...)					\
>> +	printk(KERN_NOTICE KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +#define pr_info_cont(fmt, ...)					\
>> +	printk(KERN_INFO KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
>> +/* no pr_debug_ratelimited, it doesn't make sense with CONFIG_DYNAMIC_DEBUG. */
>> +
>>  extern const struct file_operations kmsg_fops;
>>  
>>  enum {
>