Messages in this thread | | | Date | Fri, 25 Apr 2014 00:12:06 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [PATCH] printk: Print cpu number along with time |
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On Thu, 24 Apr 2014, Greg Kroah-Hartman wrote:
> > +#ifdef CONFIG_PRINTK_CPU > > + if (!buf) > > + return snprintf(NULL, 0, "[%5lu.000000,%02x] ", > > %02x for a cpu? What happens on machines with 8k cpus?
Ummm ... what issue do you see here, Greg? It'll print 0x1f40, no?
> And is this really an issue? Debugging by using printk is fun, but not > really something that people need to add a cpu number to. Why not just > use a tracepoint in your code to get the needed information instead?
Well, if you have dmesg dump from panic that happens every other year, and you have to do post-mortem analysis on it, I am pretty sure you would love to be able to figure out how the stack traces would look like without inter-CPU interleaving. And I am pretty sure you wouldn't want to insert/enable a tracepoint and wait another two years for the bug to trigger again.
-- Jiri Kosina SUSE Labs
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