From: Herbert Xu Subject: Re: [PATCH v2] crypto/caam: add backlogging support Date: Thu, 24 Sep 2015 10:47:18 +0800 Message-ID: <20150924024718.GA27355@gondor.apana.org.au> References: <1442434361-15123-1-git-send-email-alexandru.porosanu@freescale.com> <20150918132443.GG7638@gondor.apana.org.au> <20150918135017.GA9152@gondor.apana.org.au> <20150918141040.GL9249@gondor.apana.org.au> <20150923120200.GA21368@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-crypto@vger.kernel.org" , Geanta Neag Horia , Pop Mircea To: Porosanu Alexandru Return-path: Received: from helcar.hengli.com.au ([209.40.204.226]:55239 "EHLO helcar.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756427AbbIXCrV (ORCPT ); Wed, 23 Sep 2015 22:47:21 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: On Wed, Sep 23, 2015 at 02:40:32PM +0000, Porosanu Alexandru wrote: > > Yes, you are absolutely right. In this case, I have some reasons why I wouldn't like to use a crypto_queue based approach: > > 1) we've prototyped a crypto_queue implementation which did not reach the performance expectations due to CPU overhead; I'm not saying that you should always use a software queue. The queue is only needed when your hardware queue is full. You can make it zero-length for requests that are not MAY_BACKLOG, i.e., only MAY_BACKLOG requests need to be queued, everything else can just be dropped when the hw queue is full. If you do that I don't see why the performance should be any different. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt