[Devel] [RFC rh7 v4] ve/tty: vt -- Implement per VE support for console and terminals

[Andrey Ryabinin]

On 08/21/2015 06:22 PM, Cyrill Gorcunov wrote:
> On 08/21/2015 05:15 PM, Vladimir Davydov wrote:
>>> +#define vtty_printk(fmt, ...)							\
>>> +	printk("vtty: %20s: %4d: " fmt,						\
>>> +	       __func__, __LINE__, ##__VA_ARGS__)
>>> +#define vtty_printk_one(__tty)							\
>>> +	vtty_printk("tty %p idx %2d cnt %2d fl 0x%-8lx\n",			\
>>> +		    (__tty), (__tty)->index, (__tty)->count, (__tty)->flags)
>>> +#define vtty_printk_pair(__tty)							\
>>> +	vtty_printk("tty %p idx %2d cnt %2d fl 0x%-8lx "			\
>>> +		    "link %p idx %2d cnt %2d fl 0x%-8lx\n",			\
>>> +		    (__tty), (__tty)->index, (__tty)->count, (__tty)->flags,	\
>>> +		    (__tty)->link, (__tty)->link ? (__tty)->link->index : -1,	\
>>> +		    (__tty)->link ? (__tty)->link->count : -1,			\
>>> +		    (__tty)->link ? (__tty)->link->flags : -1ul)
>>
>> tty_io.c uses pr_debug. Why should we be different?
> 
> Because if you run kernel with "debug" by now it would spam the log
> too much ;/ Also I would like to not print all this even in debug
> mode but only when it's explicitly requested on compile time because
> frankly there is no much point in spamming the kernel.
> 

AFAIR "debug" in kernel command line doesn't enable pr_debug() messages.
pr_debug() works if file was compiled with '#define DEBUG' or if 
these messages were enabled in runtime (you need CONFIG_DYNAMIC_DEBUG=y for that,
see Documentation/dynamic-debug-howto.txt).

So, it sounds like that pr_debug() is exactly what you need ;)