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DateSun, 11 Jan 2009 00:11:27 +0100
FromIngo Molnar <>
SubjectRe: [PATCH 08/16] dma-debug: add core checking functions
* Joerg Roedel <joerg.roedel@amd.com> wrote:

> +#define err_printk(dev, format, arg...) do {			\
> +		error_count += 1;				\
> +		if (show_all_errors || show_num_errors > 0) {	\
> +			WARN(1, "%s %s: " format,		\
> +			     dev_driver_string(dev),		\
> +			     dev_name(dev) , ## arg);		\
> +		}						\
> +		if (!show_all_errors && show_num_errors > 0)	\
> +			show_num_errors -= 1;			\

Note that the arithmetics here is SMP-unsafe: we only hold the hash bucket 
so if two errors hit at once on two CPUs then the error tracking variables 
can be accessed at once.

I'd suggest a simple global lock for this error case (taken inside the 
hash bucket lock), to be on the safe side.

Also, please dont use a macro for this - printk details can be passed in 
to helper inlines/functions too.

	Ingo


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