Reset MSR_PKG_POWER_LIMIT Lock (63) bit

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Reset MSR_PKG_POWER_LIMIT Lock (63) bit

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I see that the Lock (63) bit is set in the MSR_PKG_POWER_LIMIT on our Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz, which is running a Dell Bios. This can be seen when I read the MSR on the two sockets.

cpu0: MSR_PKG_POWER_LIMIT: 0x800683f0005a8348 (locked)

cpu1: MSR_PKG_POWER_LIMIT: 0x800683f0005a8348 (locked)

Once this bit is locked, it ignores any further writes till next reboot making it impossible to power cap the machine. I thought that there may be some setting in the BIOS which could enable this, however I am not able to find it.

I would be grateful if you or anyone could help me in this regard.

Thanks,

Sridutt

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