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Date:   Fri, 30 Aug 2019 14:19:48 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     shuah <shuah@kernel.org>
Cc:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Brendan Higgins <brendanhiggins@google.com>,
        Joe Perches <joe@perches.com>, kunit-dev@googlegroups.com,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        frowand.list@gmail.com, sboyd@kernel.org, pmladek@suse.com,
        sergey.senozhatsky@gmail.com, rostedt@goodmis.org,
        Randy Dunlap <rdunlap@infradead.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [PATCH v2] kunit: fix failure to build without printk
Message-ID: <20190830051941.GA3598@jagdpanzerIV>
References: <20190828093143.163302-1-brendanhiggins@google.com>
 <20190828094929.GA14038@jagdpanzerIV>
 <8b2d63bf-56cd-e8f5-e8ee-2891c2c1be8f@kernel.org>
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On (08/29/19 11:01), shuah wrote:
[..]
> Hi Sergey,
> 
> What are the guidelines for using printk(). I recall some discussion
> about not using printk(). I am seeing the following from checkpatch
> script:

Hello,

> WARNING: Prefer [subsystem eg: netdev]_level([subsystem]dev, ... then
> dev_level(dev, ... then pr_level(...  to printk(KERN_LEVEL ...
> #105: FILE: include/kunit/test.h:343:
> +	printk(KERN_LEVEL "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)
> 

Oh, right.
So we sort of want people to use pr_err()/pr_info()/pr_"level"()
because, otherwise, when people use plain printk(), they tend to
forget to add KERN_LEVEL.

In kunit case everything looks fine. KERN_LEVEL is there so I'm
fine with the patch.

You still can switch to pr_info()/pr_err()/pr_etc, just to make
checkpatch happier, but that's up to you.

> Is there supposed to be pr_level() - I can find dev_level()

No, not really. pr_level() stands for pr_"debug"()/pr_"info"()/etc.

E.g.

#define pr_emerg(fmt, ...) \
        printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
#define pr_alert(fmt, ...) \
        printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_crit(fmt, ...) \
        printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_err(fmt, ...) \
        printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
#define pr_warning(fmt, ...) \
        printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
#define pr_warn pr_warning
#define pr_notice(fmt, ...) \
        printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
#define pr_info(fmt, ...) \
        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)

	-ss