On Tue, Jan 28, 2020 at 03:50:14PM +0000, Horia Geanta wrote: > On 1/22/2020 12:46 PM, Corentin Labbe wrote: > > Some bykeshedding are unnecessary since a workqueue can only be executed > > one by one. > > This behaviour is documented in: > > - kernel/kthread.c: comment of kthread_worker_fn() > > - Documentation/core-api/workqueue.rst: the functions associated with the work items one after the other > [...] > > @@ -73,16 +73,6 @@ static void crypto_pump_requests(struct crypto_engine *engine, > > > > spin_lock_irqsave(&engine->queue_lock, flags); > > > > - /* Make sure we are not already running a request */ > > - if (engine->cur_req) > > - goto out; > > - > This check is here for a good reason, namely because crypto engine > cannot currently handle multiple crypto requests being in "flight" > in parallel. > > More exactly, if this check is removed the following sequence could occur: > crypto_pump_work() -> crypto_pump_requests() -> .do_one_request(areq1) > crypto_pump_work() -> crypto_pump_requests() -> .do_one_request(areq2) > crypto_finalize_request(areq1) > crypto_finalize_request(areq2) > As explained in the commitlog, crypto_pump_work() cannot be ran twice. Regards
