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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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