On Mon, Dec 07, 2009 at 05:55:37PM +0100, Thomas Gleixner wrote: ... > > And, btw if some code is trying to write to apic when > > it's disabled via boot option -- it means the code is > > buggy and this is not a false positive but rather proper > > warning. > > > > Thomas, if you've changed this code I suppose you saw some > > warning triggered, right? Could you pointed me on it? > > http://www.kerneloops.org/searchweek.php?search=native_apic_write_dummy > Doh! The most cases show inapropriate usage of apic->write() operation. set_perf_event_pending() already fixed by 7d42896628202a551ad1107697cd215dc5fca099, intel_init_thermal() fixed as well with 5ce4243dcefbbc43791ffc36e1be55067ceec916 (all was in -tip). Though throttling code is just buggy and intel_init_thermal() should check if cpu_has_apic. So the former code does exactly what it should -- it catches inapropriate writes. Thomas, I just don't know -- from my pov, write() is really different from read(), since it implies that APIC changes it behaviour, it could be timer setup, vector setup operation or whatever. I even doubt if enabling IPI in apic-noop is a good idea (since perf code already implemented to check apic presence by Peter and IPI is not called). Though I'm not insisting, I simply don't have spare time at moment to check all apic_writes() again :( -- Cyrill -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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