On 05.11.2012 14:46, Shawn Guo wrote: >>> From my quick testing on imx23 with printk timestamp, it's not OK, >>> so we may need to leave imx23 out there. >> > I should say it's practically not OK since it wraps in such a short > period. But it actually works as expected. > >> Hmm, does it wrap after 2 seconds? > > Yes, it does wrap after ~2 seconds. This is weird. AFAIK the printk should be using sched_clock(), which is a weak symbol overridden in arch/arm/kernel/sched_clock.c and it should take care of the extension to never-ever-wrapping 64-bit timestamp. Looks that it does not and if it does not, I think there is more to be worried of than just printk timestamps. I don't see anything wrong with the code; bumping the 64-bit part so that it is no more than wrap time away should take place in sched_clock_timer which is called at 90% of the time interval. BTW this patch deserves IMHO looking at https://patchwork.kernel.org/patch/1193631/ but it is probably not the problem here. In case it matters I'm working with the current 3.4 with RT patches (none of them touches arch/arm/mach-mxs) - sorry not to mention it earlier, I forgot to write it again after I included additional mailing lists to the discussion. Regards -- Stano -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
