From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8EB3C43331 for ; Fri, 27 Mar 2020 11:05:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4E45206F1 for ; Fri, 27 Mar 2020 11:05:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726215AbgC0LF0 convert rfc822-to-8bit (ORCPT ); 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-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@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)