Re: [PATCH] random: always use batched entropy for get_random_u{32,64}

[Tony Luck]

Also ... what's the deal with a spin_lock on a per-cpu structure?

        batch = raw_cpu_ptr(&batched_entropy_u64);
        spin_lock_irqsave(&batch->batch_lock, flags);
        if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
                extract_crng((u8 *)batch->entropy_u64);
                batch->position = 0;
        }
        ret = batch->entropy_u64[batch->position++];
        spin_unlock_irqrestore(&batch->batch_lock, flags);

Could we just disable interrupts and pre-emption around the entropy extraction?

-Tony