Messages in this thread | | | Date | Sun, 19 Sep 2004 16:07:38 +0200 | From | Dominik Brodowski <> | Subject | boot_cpu_data vs current_cpu_data in voluntary-preempt-2.6.9-rc2-mm1-S1 |
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Ingo,
Your voluntary-preempt-2.6.9-rc2-mm1-S1 patch contains this change
@@ -34,7 +34,7 @@ inline void __const_udelay(unsigned long xloops *= 4; __asm__("mull %0" :"=d" (xloops), "=&a" (d0) - :"1" (xloops),"0" (current_cpu_data.loops_per_jiffy * (HZ/4))); + :"1" (xloops),"0" (boot_cpu_data.loops_per_jiffy * (HZ/4))); __delay(++xloops); }
for both x86 and x86_64. And it's wrong. It assumes loops_per_jiffy being consistent on all CPUs. There _are_ asymetric multiprocessor systems out there, and some SMP systems can become asymetric as soon as frequency scaling is enabled. Using boot_cpu_data's loops_per_jiffy instead of current_cpu_data's loops_per_jiffy causes delays being too short or too long. So please drop this change.
Thanks, Dominik - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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