Messages in this thread |  | | | Date | Wed, 14 Jan 2009 12:48:29 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH 08/16] dma-debug: add core checking functions |
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* Joerg Roedel <joerg.roedel@amd.com> wrote:
> On Sun, Jan 11, 2009 at 12:11:27AM +0100, Ingo Molnar wrote: > > > > * 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. > > As I wrote in a previous email, a race here is no big deal. I add a > comment to document it. Or do we want another global lock here?
we commonly use global locks in debug exception cases - to serialize console output. But it's certainly no big deal.
Ingo
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