Am Thu, May 12, 2022 at 06:37:48PM +0200 schrieb Jason A. Donenfeld: > Since crng_ready() is only false briefly during initialization and then > forever after becomes true, we don't need to evaluate it after, making > it a prime candidate for a static branch. > > One complication, however, is that it changes state in a particular call > to credit_init_bits(), which might be made from atomic context, which > means we must kick off a workqueue to change the static key. Further > complicating things, credit_init_bits() may be called sufficiently early > on in system initialization such that system_wq is NULL. > > Fortunately, there exists the nice function execute_in_process_context(), > which will immediately execute the function if !in_interrupt(), and > otherwise defer it to a workqueue. During early init, before workqueues > are available, in_interrupt() is always false, because interrupts > haven't even been enabled yet, which means the function in that case > executes immediately. Later on, after workqueues are available, > in_interrupt() might be true, but in that case, the work is queued in > system_wq and all goes well. Reviewed-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> Thanks, Dominik
