Nick Piggin <[EMAIL PROTECTED]> wrote: > > Andrew Morton wrote: > > > > > yup. > > > > > >>Why not use something like do_gettimeofday? (or I'm sure one > >>of our time keepers can suggest the right thing to use). > > > > > > do_gettimeofday() takes locks, so a) we can't do printk from inside it and > > Dang, yeah maybe this is the showstopper. > > > b) if you do a printk-from-interupt and the interrupted code was running > > do_gettimeofday(), deadlock. > > > > What about just using jiffies, then? > > Really, sched_clock() is very broken for this (I know you're > not arguing against that). > > It can go backwards when called twice from the same CPU, and the > number returned by one CPU need have no correlation with that > returned by another.
jiffies wouldn't have sufficient resolution for this application. Bear in mind that this is just a debugging thing - it's better to have good resolution with occasional theoretical weirdness than to have poor resolution plus super-consistency, IMO. > However, I understand you probably just want something quick and > dirty for 2.6.13 and would be happy just if it isn't more broken > than before ;) We're OK for 2.6.13, I think. ia64 people will quickly learn to not turn the option on. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
