Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [rfc patch] i386: don't save eflags on task switch | Date | Sun, 5 Nov 2006 18:01:18 +0100 |
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> sti is expensive as well; iirc just as expensive on most processors as > popf,
On K8 STI is 4 cycles.
> although I don't have hard numbers to back this up on hand. An > _unlikely_ jcc + popf? is better than a sti, for sure, but a likely > jcc+popf could cost more than a jcc+sti, depending on model.
99.9999% of all restore_flags just need STI.
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