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I thought that Intel added the ‘pause’ instruction to make busy spinning more power friendly
by secondcoming 1y ago
I thought that Intel added the ‘pause’ instruction to make busy spinning more power friendly
- jeffbee 1y agox86 has always had PAUSE, what they did is they made the PAUSE way longer in Skylake-X which threw everyone off guard. But yeah, x86 ISA extensions cover this ground very well. Atom, the low-power server line, introduced UMWAIT and TPAUSE that enable cores to briefly enter a power-saving active state while waiting for something to happen. These instructions later came to mainstream Core and Xeon CPUs because Intel made those frankenchips with Atoms and Cores together.
- secondcoming 1y agoIt had REP NOP which is the same opcode as PAUSE, but on CPUs that supported it PAUSE does less work for the same effect. At least that's my understanding of it.