Messages in this thread | | | Date | Thu, 24 Jul 2008 17:13:24 +0200 | From | Martin Wilck <> | Subject | Re: [PATCH] x86 (64): make calibrate_APIC_clock() SMI-safe |
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Hi Cyrill,
> btw, Martin, don't get me wrong please - i'm not just complaining :) > The changes you propose is important enough _but_ it could introduce > regression. Look, with situation of miscalibrated apic timer kernel > was working before but with the patch it could stop to work. So if > user has a such screwed motherboard he could be shocked if it stop > booting with message about SMI happened. we defenitely have to provide > some workaround for this. And your max iteration counter solution > would be fine I think.
Let's see what other people think about this. I am fine with both solutions. Currently only the first one has been tested though (testing these patches thoroughly needs long-time reboot tests).
One more remark: There are similar calibration routines around in the kernel which suffer from similar problems as calibrate_APIC_clock(). AFAIK, only calibrate_delay() was made SMI-safe by Venkatesh Pallipadi years ago.
Martin
-- Martin Wilck PRIMERGY System Software Engineer FSC IP ESP DEV 6
Fujitsu Siemens Computers GmbH Heinz-Nixdorf-Ring 1 33106 Paderborn Germany
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