Messages in this thread | | | Date | Tue, 27 Mar 2007 00:12:53 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [patch 1/2] Ignore stolen time in the softlockup watchdog |
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Eric Dumazet wrote: > Jeremy Fitzhardinge a écrit : > >> +static DEFINE_PER_CPU(unsigned long long, touch_timestamp); > > ... > >> void touch_softlockup_watchdog(void) >> { >> - __raw_get_cpu_var(touch_timestamp) = jiffies; >> + __raw_get_cpu_var(touch_timestamp) = sched_clock(); >> } > > Not very clear if this is safe on 32bit, since this is not anymore > atomic.
Hm, good point. Don't think it matters very much. These values are per-cpu, and if an interrupt happens between the word updates and the intermediate values causes a timeout, then it was pretty marginal anyway. I guess the worst case is if the low-word gets written first, and it goes from a high value to low, then it could be sampled as if time had gone back by up to ~4 seconds.
I'll give it another look.
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