Messages in this thread |  | | Date | Thu, 01 Nov 2001 03:21:25 -0800 | From | george anzinger <> | Subject | Re: [Patch] Re: Nasty suprise with uptime |
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Tim Schmielau wrote: ~snip > @@ -683,6 +683,34 @@ > if (TQ_ACTIVE(tq_timer)) > mark_bh(TQUEUE_BH); > } > + > + > +#if BITS_PER_LONG < 48 > + > +u64 get_jiffies64(void) > +{ > + static unsigned long jiffies_hi = 0; > + static unsigned long jiffies_last = INITIAL_JIFFIES; > + unsigned long jiffies_tmp; > + > + jiffies_tmp = jiffies; /* avoid races */ > + if (jiffies_tmp < jiffies_last) /* We have a wrap */ > + jiffies_hi++; > + jiffies_last = jiffies_tmp; > + > + return (jiffies_tmp | ((u64)jiffies_hi) << BITS_PER_LONG);
Doesn't this need to be protected on SMP machines? What if two cpus call get_jiffies64() at the same time... Seems like jiffies_hi could get bumped twice instead of once.
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