Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [Announce] Linux-tiny project revival | Date | Thu, 27 Sep 2007 09:00:36 +0200 |
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On Thursday 20 September 2007, you wrote: > So instead of: > printk(KERN_NOTICE "Fruit=%d\n", banana); > It would now be: > printk(KERN_NOTICE, "Fruit=%d\n", banana); > > Change the header from: > #define KERN_NOTICE "<5>" > to: > #define KERN_NOTICE 5 > > Then you can change the printk guts to do something vaguely like (untested): > #define printk(arg1, arg2, ...) actual_printk("<" #arg1 ">" arg2, __VA_ARGS__) > > And so far no behavior has changed. But now the _fun_ part is, you can add a > config symbol for "what is the minimum loglevel I care about?" Set that as a > number from 0-9. And then you can define the printk to do: > > #define printk(level, str, ...) \ > do { \ > if (level < CONFIG_PRINTK_DOICARE) \ > actual_printk("<" #level ">" str, __VA_ARGS__); \ > } while(0); >
Assuming that we want to go down that road, I think you can do better with more evil macro magic, by using something along the lines of
#define KERN_NOTICE "<5>",
#define PRINTK_CONTINUED "",
#define printk(level, str, ...) \ do { \ if (sizeof(level) == 1) /* continued printk */\ actual_printk(str, __VA_ARGS__); \ else if ((level[1] - '0') < CONFIG_PRINTK_DOICARE) \ actual_printk(level str, __VA_ARGS__); \ } while(0);
Then you don't have to change every single printk in the kernel, but only those that don't currently come with a log level. More importantly, you can do the conversion without a flag day, by spreading (an empty) PRINTK_CONTINUED in places that do need a printk without a log level.
Arnd <>< - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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