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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47f85bb5a46sm12996832f8f.9.2026.07.23.01.01.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jul 2026 01:01:18 -0700 (PDT) Date: Thu, 23 Jul 2026 09:01:13 +0100 From: David Laight To: Simon Richter Cc: Eric Biggers , Hendrik Donner , linux-crypto@vger.kernel.org, Herbert Xu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Steffen Klassert , Thomas Huth Subject: Re: [PATCH 1/2] crypto: pcrypt - Remove pcrypt Message-ID: <20260723090113.5c2b9995@pumpkin> In-Reply-To: References: <20260713223234.24812-1-ebiggers@kernel.org> <20260713223234.24812-2-ebiggers@kernel.org> <37ecba68-947a-45ad-9ec4-361facc06a05@os-cillation.de> <20260721195004.GA3383223@google.com> <19613c3e-9756-45fc-84b6-b650ba3723a7@os-cillation.de> <20260722194023.GB2118@quark> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 23 Jul 2026 08:30:47 +0900 Simon Richter wrote: > Hi, > > On 7/23/26 4:40 AM, Eric Biggers wrote: > > > So while maybe pcrypt does still help a bit on this platform for now, > > the approach does seem quite dated and largely a workaround for > > inefficiencies elsewhere in the stack (including systems where the > > optimized crypto code is accidentally not enabled). > > There is one additional aspect: offloading frees the CPU to do something > else -- and that is where even offload engines that are slower than the > CPU can still be beneficial in the big picture. Provided what is being offload actually takes long enough to allow for setting up the iommu, the two context switches and the interrupt as well as the obvious setup costs. David > > Simon >