On Tue, 2016-10-18 at 15:08 +0100, Ard Biesheuvel wrote: > > + aead_req = *this_cpu_ptr(ccmp->reqs); > + if (!aead_req) { > + aead_req = kzalloc(reqsize + CCM_AAD_LEN, GFP_ATOMIC); > + if (!aead_req) > + return -ENOMEM; > + *this_cpu_ptr(ccmp->reqs) = aead_req; > + aead_request_set_tfm(aead_req, ccmp->tfm); > + } Hmm. Is it really worth having a per-CPU variable for each possible key? You could have a large number of those (typically three when you're a client on an AP, and 1 + 1 for each client when you're the AP). Would it be so bad to have to set the TFM every time (if that's even possible), and just have a single per-CPU cache? johannes