Re: [PATCH] x86: enable preemption in delay
From: Pavel Machek <hidden>
Date: 2008-06-01 14:18:51
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On Wed 2008-05-28 09:01:06, Steven Rostedt wrote:
On Sun, 25 May 2008, Pavel Machek wrote:quoted
quoted
+ if (unlikely(cpu != smp_processor_id())) { + if (loops <= TSC_MIGRATE_COUNT) + break; + cpu = smp_processor_id(); + rdtscl(bclock); + loops -= TSC_MIGRATE_COUNT; + } else { + rdtscl(now); + if ((now - bclock) >= loops) + break; + loops -= (now - bclock); + bclock = now;What happens with different cpus running on different frequencies...? Cpufreq?It's not even protected with the old code.
Maybe, but it is simple to fix as long as preemption is disabled. When you enable it, it becomes much harder. Lets get that fixed. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html