On Mon, Nov 23, 2020 at 04:57:46PM +0100, Marco Elver wrote: > Let me know what you prefer. >
> @@ -288,27 +288,19 @@ static u32 kcsan_prandom_u32_max(u32 ep_ro) > u32 res; > > /* > + * Avoid recursion with scheduler by disabling KCSAN because > + * preempt_enable_notrace() will still call into scheduler code. > */ > + kcsan_disable_current(); > preempt_disable_notrace(); > state = raw_cpu_ptr(&kcsan_rand_state); > res = prandom_u32_state(state); > + preempt_enable_notrace(); > + kcsan_enable_current_nowarn(); > > return (u32)(((u64) res * ep_ro) >> 32); > } This is much preferred over the other. The thing with _no_resched is that you can miss a preemption for an unbounded amount of time, which is bad. The _only_ valid use of _no_resched is when there's a call to schedule() right after it.
