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SubjectRe: printk loglevel policy?
Randy.Dunlap wrote:
> Keith Owens wrote:
>
>> On Sun, 02 Jan 2005 13:41:34 -0800, "Randy.Dunlap" <rddunlap@osdl.org>
>> wrote:
>>
>>> Jim Nelson wrote:
>>>
>>>> Or does printk() do some tracking that I didn't see as to where in
>>>> the kernel the strings are coming from?
>>>
>>>
>>> That kind of garbled output has been known to happen, but
>>> the <console_sem> is supposed to prevent that (along with
>>> zap_locks() in kernel/printk.c).
>>
>>
>>
>> Using multiple calls to printk to print a single line has always been
>> subject to the possibility of interleaving on SMP. We just live with
>> the risk. Printing a complete line in a single call to printk is
>> protected by various locks. Print a line in multiple calls is not
>> protected. If it bothers you that much, build up the line in a local
>> buffer then call printk once.
>
>
> True, I was thinking about the single line case, which I
> have seen garbled/mixed in the past (on SMP). Hopefully
> that one is fixed.
>

Okay, that answered my question. Is is frowned upon to use strncat/strcat in the
kernel? I have yet to see any use of them outside of the definition in
lib/string.c. It would seem to be faster (less potential contention for the
printk locks).
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