Re: [PATCH] Cleanup cpu loop

Avi Kivity
2009-06-22T13:30:07Z

On 06/18/2009 03:22 PM, Gleb Natapov wrote:
> Rearrange cpu loop to be (hopefully) more readable. Put difference
> between kernel/userspace irqchip in one place.
>
>
> static void flush_queued_work(CPUState *env)
> @@ -1877,6 +1871,8 @@ static void update_regs_for_init(CPUState *env)
> #endif
>
> cpu_reset(env);
> + /* cpu_reset() clears env->halted, cpu should be halted after init */
> + env->halted = 1;
>

How does that work for the boot cpu?

> static int kvm_main_loop_cpu(CPUState *env)
> {
> setup_kernel_sigmask(env);
> @@ -1935,19 +1941,14 @@ static int kvm_main_loop_cpu(CPUState *env)
> kvm_arch_load_regs(env);
>
> while (1) {
> - while (!has_work(env))
> - kvm_main_loop_wait(env, 1000);
> - if (env->interrupt_request& (CPU_INTERRUPT_HARD | CPU_INTERRUPT_NMI))
> - env->halted = 0;
> - if (!kvm_irqchip_in_kernel(kvm_context)) {
> - if (env->kvm_cpu_state.init)
> - update_regs_for_init(env);
> - if (env->kvm_cpu_state.sipi_needed)
> - update_regs_for_sipi(env);
> + int run_cpu = is_cpu_stopped(env) ? 0 : 1;
>

run_cpu = !is_cpu_stopped()

> + if (run_cpu&& !kvm_irqchip_in_kernel(kvm_context)) {
> + process_irqchip_events(env);
> + run_cpu = !env->halted;
> }
> - if (!env->halted || kvm_irqchip_in_kernel(kvm_context))
> - kvm_cpu_exec(env);
> - kvm_main_loop_wait(env, 0);
> + kvm_main_loop_wait(env, run_cpu ? 0 : 1000);
> + if (run_cpu)
> + kvm_cpu_exec(env);
> }
>

A single conditional may be clearer:

if (run_cpu)
kvm_main_loop_wait(0)
kvm_cpu_exec()
else
kvm_main_loop_wait(1000)

--
error compiling committee.c: too many arguments to function