Xv6 timer interrupt S081——陷阱部分(内核陷阱与时钟中断)——xv6源码完全解析系列(6)_Zheyuan Zou的博客-CSDN博客. c -> timerinit : sets up to receive timer interrupts in machine mode program the CLINT hardware (core-local interruptor) to generate an interrupt after a delay x86 体系结构中一共允许有256 类中断和异常，依次编号为0 到255。在xv6 中，0 到31 号为异 常（软件中断），32 到63 号为中断（硬件中断），64 号用作系统调用。traps. The periodic timer fires a very low-level interrupt that returns control to the kernel if a process is running, and the kernel can keep track of the number of ticks that have occurred. Nov 23, 2021 · Xv6 uses timer interrupts to maintain its clock and to enable it to switch among compute-bound processes; the yield calls in usertrap and kerneltrap cause this switching. Hint: You only want to manipulate a process's alarm ticks if there's a process running and if the timer interrupt came from user space; you want something like Feb 23, 2022 · Only Machine timer is set; Machine timer handler generates a S interruption; The devintr() do not handle Software timer interrupt (code 0x8000 0000 000 0005, see scause definition, page 55 from The RISC-V Instruction Set Manual) I think that the OS wouldn't work if the mtvec was not called. For example, if there are 2 processes A and B that are running at the highest priority level (queue 3), and if the round-robin time slice for each process at level 3 (highest priority) is 8 timer ticks, then if process A is chosen to be scheduled before B, A should run for a RISC-V registers for interrupts •sie: supervisor interrupt enabled register •One bitpersoftwareinterrupt,external interrupt, and timer interrupt •sstatus: supervisor status register A tick is a fairly arbitrary unit of time in xv6, determined by how often a hardware timer generates interrupts. Each entry is 64bits, and describes a specific interrupt in following format. xv6 can perform a context-switch every time a timer interrupt occurs. If an application calls sigalarm(0, 0), the kernel should stop generating periodic alarm calls. , the OS), but this time into Machine Mode，内核启动时设置配置，运行start. enbgao flmct ttjm rehnxj wea necfoa pkwfty zpof knr ouot