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The realtime preemption mini-summit

The realtime preemption mini-summit

Posted Sep 29, 2009 9:23 UTC (Tue) by nix (subscriber, #2304)
In reply to: The realtime preemption mini-summit by niv
Parent article: The realtime preemption mini-summit

It's a bit unfortunate that the ability to have the OS actually control the machine is relegated to a "premium real-time mode" on "select platforms". *Everything* should work like this.

The only tolerable use for SMIs IMNSHO is emergency thermal control, i.e. keeping the hardware safe...

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The realtime preemption mini-summit

Posted Oct 4, 2009 13:51 UTC (Sun) by dvhart (subscriber, #19636) [Link]

There are other less known uses for SMIs that are an unfortunately reality of our world. Fixing hardware bugs is one. A buggy instruction for instance can get emulated under an SMI. It would be wonderful if those things never existed, but in practice, that just isn't the case.

The realtime preemption mini-summit

Posted Oct 5, 2009 19:10 UTC (Mon) by bdonlan (guest, #51264) [Link]

Buggy instructions can also be fixed in the kernel, however, and at least then you know about them. While this may be a bit unfeasable for Windows, there should be some kind of switch Linux can use to disable the SMI handling, and just pass things to the normal #UD handler. If you then include hooks for any operations needing emulation at the same time as loading new microcode to disable the hardware support, no problem.

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