Messages in this thread | | | Date | Thu, 19 Apr 2012 09:06:30 -0400 | From | Prarit Bhargava <> | Subject | Re: [PATCH] clocksource, prevent overflow in clocksource_cyc2ns |
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On 04/19/2012 08:52 AM, Thomas Gleixner wrote: > On Thu, 19 Apr 2012, Thomas Gleixner wrote: > >> On Wed, 18 Apr 2012, John Stultz wrote: >>> On 04/18/2012 04:59 PM, Prarit Bhargava wrote: >>>>
>> No. The show_state() part prints into the buffer. But it's not >> guaranteed that the buffer is flushed right away. It could be flushed >> later as well in a different context. And of course the flush code >> runs with interrupts disabled and dumping out a gazillion of lines >> over serial will cause the same hickup. Just planting random >> touch_watchdog() calls into the code is not the right approach, >> really. >> >> We should think about the reasons why we have interrupts disabled for >> so much time. Is that really, really necessary ?
In the case of the sysrq-t, I would argue that it is. The whole point behind the sysrq-t is that we're capturing the *current* state of the system. Having that output effected by interrupts seems like a bad idea.
> > I'm not against making the clocksource code more robust, but I don't > want to add crap there just to cope with complete madness elsewhere.
Maybe I came off the wrong way but I completely agree with that sentiment. Like yourself, I'm looking for a correct fix rather than a fast fix.
Sorry that I haven't provided any debug info but I'm still in the gathering data stage atm. It was just John's ping that made me "brain dump" the current info I had.
P.
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