Received: by 2002:a25:6193:0:0:0:0:0 with SMTP id v141csp2356542ybb; Fri, 27 Mar 2020 04:06:56 -0700 (PDT) X-Google-Smtp-Source: ADFU+vuiPm47kUK/H7KCMbmW/+VkJ0MyF/pPfKubgH8QimviQ9Us3f50Qb62W9S6sf+teijCd0TL X-Received: by 2002:aca:4986:: with SMTP id w128mr3381645oia.46.1585307216729; Fri, 27 Mar 2020 04:06:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1585307216; cv=none; d=google.com; s=arc-20160816; b=wonu3Ce48cdBxDJgzpFiFo91umBPH6hj/UgLAiDtnk4eNTADgPOkHRuUprFJuSdgg1 ncKoyMGu83nmPiMRB3qokuGhPyscFlTPLRBNBt8KAIVBKLi0GO9/taioado9CEmT/ExE ch+NOwHI0v9GM8PqFTLEp6yOdOT6Eula+G9JZROIbNZRSMOX6xoRRhM1FFrsCf22ohWk 17vu0nqVHy9jPFyEIPrRuej7zYpTkKgI58GXSUVQ5SCHif3xhdb2+iyAn3OQm24Sc+7E iZ1YIzAN2Z5vSnWwRM6iBeNy1va3OneSgFeEQHvaNBvdLbEFIPk+qvvkq/MNtV2av88h 9f5Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :message-id:date:references:in-reply-to:subject:to:from; bh=eEhSmft+h4E9cupAWUu5Wa7w7NSA/iU9psBt7EqH614=; b=oHBNfKwNEG+IBVYy1ENaoa0R1kinOMIlbpAdzTjv7039JvMsbiagXM2L9ghQz5/MaX qJSnYe/2zomueZlHXV2xZTlsNPTYo3VK4w9Uwxy4EaGfeIwO67AplNw5kvj0ns2dwJYF UyrNh8gPMaefOigeh/gTUhMKi7Pa624VX+KdCErNCX+yBQiGcogZlNqmkKmshchNA6kW KbBk1F7SC41nHVWQwHG7U+U/t7yM1ufWdlGEGDBXA0c/Hr4nRKdLCkKKV2UCMxToGKgl OAvffY8/+4DPmi6+XdNXxsQ3ZmtMgNFE1bKbVvLJAkBcYQOE68x18fnWodDaSoIcNaK/ YYkA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id j206si2389774oia.158.2020.03.27.04.06.43; Fri, 27 Mar 2020 04:06:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726465AbgC0LF0 convert rfc822-to-8bit (ORCPT + 99 others); Fri, 27 Mar 2020 07:05:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:59720 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726165AbgC0LF0 (ORCPT ); Fri, 27 Mar 2020 07:05:26 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 78030ADFE; Fri, 27 Mar 2020 11:05:24 +0000 (UTC) From: =?utf-8?Q?Aur=C3=A9lien?= Aptel To: Long Li , "longli\@linuxonhyperv.com" , Steve French , "linux-cifs\@vger.kernel.org" , "samba-technical\@lists.samba.org" , "linux-kernel\@vger.kernel.org" Subject: RE: [PATCH] cifs: Remove locking in smb2_verify_signature() when calculating SMB2/SMB3 signature on receiving packets In-Reply-To: References: <1585159997-115196-1-git-send-email-longli@linuxonhyperv.com> <87d08zzbg6.fsf@suse.com> Date: Fri, 27 Mar 2020 12:05:23 +0100 Message-ID: <877dz6njm4.fsf@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Long Li writes: >>need for locks). AFAIK there's no state that need to be kept between >>signing/encrypting calls beside the access to keys. Is it that expensive to >>create/release? > > My guess is that crypto_alloc_shash() is a heavy call? AFAIK there's no IO, just some memory allocation. Could be faster than locking. Something to look into, maybe... Cheers, -- Aurélien Aptel / SUSE Labs Samba Team GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)