From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7)
Date: Fri, 14 Oct 2016 12:00:12 +0200
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Cc: Andy Lutomirski <luto@amacapital.net>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        "linux-next@vger.kernel.org" <linux-next@vger.kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Network Development <netdev@vger.kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Linux Wireless List <linux-wireless@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jouni Malinen <j@w1.fi>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Return-path: <linux-kernel-owner@vger.kernel.org>
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> So why is the performance hit acceptable for ESP but not for WPA? We
> could easily implement the same thing, i.e.,
> kmalloc(GFP_ATOMIC)/kfree the aead_req struct rather than allocate it
> on the stack

Yeah, maybe we should. It's likely a much bigger allocation, but I
don't actually know if that affects speed.

In most cases where you want high performance we never hit this anyway
since we'll have hardware crypto. I know for our (Intel's) devices we
normally never hit these code paths.

But on the other hand, you also did your changes for a reason, and the
only reason I can see of that is performance. So you'd be the one with
most "skin in the game", I guess?

johannes