Richard Henderson <richard.hender...@linaro.org> writes:
> On 6/14/19 10:11 AM, Alex Bennée wrote:
>> start_exclusive();
>> + cpu->in_exclusive_work_context = true;
>> wi->func(cpu, wi->data);
>> + cpu->in_exclusive_work_context = false;
>> end_exclusive();
>
> Is there a reason not to put those into start/end_exclusive?
Not particularly... it can use current_cpu to find the cpu and set the
flag.
> And if not, what does in_exclusive_work_context mean?
Currently the check implies it's only for:
exclusive work context, which has previously been queued via
async_safe_run_on_cpu()
which avoids jumping through hoops if another async_safe tasks still
wants to flush the TB. However keeping it with start/end exclusive means
we could also clean up the code in:
void cpu_exec_step_atomic(CPUState *cpu)
{
..
/* volatile because we modify it between setjmp and longjmp */
volatile bool in_exclusive_region = false;
..
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
start_exclusive();
..
} else {
..
}
if (in_exclusive_region) {
..
end_exclusive();
but the volatile makes me nervous. Is it only a risk that local
variable accesses might get optimised away?
>
>
> r~
--
Alex Bennée
