NettetSince the operand spans two cache lines and the operation must be atomic, the system locks the bus while the CPU accesses the two cache lines. A bus lock is acquired through either split locked access to writeback (WB) memory … NettetIntel Instruction Set - LOCK - Lock Bus Usage: LOCK LOCK: (386+ prefix) Modifies flags: None This instruction is a prefix that causes the CPU assert bus lock signal during the execution of the next instruction. Used to avoid two processors from updating the same data location.
What does the "lock" instruction mean in x86 assembly?
Nettet24. jan. 2024 · Intel® Intrinsics Guide includes C-style functions that provide access to other instructions without writing assembly code. Skip To Main Content. ... This intrinsic generates a sequence of instructions, which may perform worse than a native instruction. Consider the performance impact of this intrinsic. NettetIn most cases, CLI clears the IF flag in the EFLAGS register and no other flags are affected. Clearing the IF flag causes the processor to ignore maskable external interrupts. The IF flag and the CLI and STI instruction have no effect on the generation of exceptions and NMI interrupts. Operation is different in two modes defined as follows: lead coldsnap wolf
3.9.3. Executing LOCK and UNLOCK JTAG Instructions - Intel
NettetThe LOCK prefix is typically used with the BTS instruction to perform a read-modify-write operation on a memory location in shared memory environment. The integrity of the … NettetInstruction prefix to indicate start of hardware lock elision, used with memory atomic instructions only (for other instructions, the F2 prefix may have other meanings). When used with such instructions, may start a transaction instead of performing the memory atomic operation. NettetThis instruction can be used with a LOCK prefix to allow the instruction to be executed atomically. In 64-bit mode, the instruction’s default operation size is 32 bits. Using a … leadco lighting