On Mon, Dec 07 2020 at 12:39, Peter Zijlstra wrote: > On Fri, Dec 04, 2020 at 06:01:58PM +0100, Thomas Gleixner wrote: >> static inline void tasklet_unlock_wait(struct tasklet_struct *t) >> { >> - while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); } >> + while (test_bit(TASKLET_STATE_RUN, &(t)->state)) >> + cpu_relax(); >> } > > Wouldn't it be nicer to stick a completion in tasklet_struct ? Or at the > very least use wait_var_event() or something?
It would be nicer. Just need to audit all possible callers. That would lose the implicit boosting of the preempted softirq thread, but these wait pathes should not be in any way relevant for user task latencies. Emphasis on should. Lemme stare at the callers including the ones which have it wrapped into some other inline just because. Thanks, tglx