This adds kernel support for some Intel instructions that allow fast access to the FS and GS 64bit base. They need some changes to entry_64.S because they allow user to fully control the GS base.
Advantages: - NMIs (and other "paranoid" interrupts) avoid one RDMSR which makes them faster - User space can use these instructions, mainly for efficient context switching with user thread libraries - Context switches do not need to use MSR writes anymore to context switch FS/GS base >4GB. This will speed up applications that have enough thread local data that it won't fit below 4GB. - User space can use GS efficiently as an additional global pointer register I also included one minor (unrelated) optimization to disable an unneeded old SWAPGS workaround. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/