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SMP alternativesSMP alternativesPosted Dec 16, 2005 17:38 UTC (Fri) by norsk (guest, #30746)Parent article: SMP alternatives
Back in 1998, while working at Novell on the Netware SMP project, I did the same thing on self-modifying kernel mods. The kernel was built in SMP mode and when installed on a UP system, all the "lock" instructions, SMP and atomics called their respective init routines to determine whether UP or SMP and applied the correct op-codes. Gave us 2-5% improvement and a major cost in shipping of different kernels.
I like the idea of reversing the mods when a CPU hotplug event occurs. Hardware at my time did not have the feature set.
I was wondering why this had not yet happened before in Linux. Still a far better world to work in, then the Netware kernel.
doug "norsk" thompson
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SMP alternatives Posted Dec 27, 2005 17:13 UTC (Tue) by cajal (subscriber, #4167) [Link] If I'm interpreting your post right, you're saying this is a bad thing. A 2-5% improvement is pretty negligible, and it came at a major cost. Sounds like this is something Linux should avoid.
SMP alternatives Posted Dec 27, 2005 23:17 UTC (Tue) by turpie (guest, #5219) [Link] He meant that it saved the major cost of shipping different kernels, by allowing them to ship a single kernel for both UP and SMP.
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