From: Benjamin Herrenschmidt Subject: Re: [PATCH V3 6/6] crypto/nx: Add P9 NX support for 842 compression engine Date: Wed, 30 Aug 2017 07:57:17 +1000 Message-ID: <1504043837.2358.38.camel@kernel.crashing.org> References: <1500699702.23205.8.camel@hbabu-laptop> <1504041817.2358.32.camel@kernel.crashing.org> <59A5E2AE.5060400@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Dan Streetman , Michael Ellerman , Herbert Xu , Linux Crypto Mailing List , "linuxppc-dev@lists.ozlabs.org" , mikey@neuling.org, suka@us.ibm.com, Ram Pai , npiggin@gmail.com, Haren Myneni To: Haren Myneni Return-path: Received: from gate.crashing.org ([63.228.1.57]:57231 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272AbdH2WYj (ORCPT ); Tue, 29 Aug 2017 18:24:39 -0400 In-Reply-To: <59A5E2AE.5060400@linux.vnet.ibm.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Tue, 2017-08-29 at 14:54 -0700, Haren Myneni wrote: > Opening send window for each crypto transform (crypto_alloc, > compression/decompression, ..., crypto_free) so that does not have to > wait for the previous copy/paste complete. VAS will map send and > receive windows, and can cache in send windows (up to 128). So I > thought using the same send window (per chip) for more requests (say > 1000) may be adding overhead. > > I will make changes if you prefer using 1 send window per chip. Did you check the cost of opening/closing a window ? Cheers, Ben.