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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 06A43C388F7 for ; Mon, 9 Nov 2020 19:31:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AE01206D8 for ; Mon, 9 Nov 2020 19:31:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730778AbgKITbG (ORCPT ); Mon, 9 Nov 2020 14:31:06 -0500 Received: from mx3.molgen.mpg.de ([141.14.17.11]:40755 "EHLO mx1.molgen.mpg.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726691AbgKITbG (ORCPT ); Mon, 9 Nov 2020 14:31:06 -0500 Received: from [192.168.0.2] (ip5f5af1fc.dynamic.kabel-deutschland.de [95.90.241.252]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id D6F902064713E; Mon, 9 Nov 2020 20:31:02 +0100 (CET) To: Herbert Xu , "David S. Miller" , Stephan Mueller Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org From: Paul Menzel Subject: jitterentropy: `jent_mod_init()` takes 17 ms Message-ID: <02fa159f-4f94-cfb7-1f88-bed91c6542a1@molgen.mpg.de> Date: Mon, 9 Nov 2020 20:31:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear Linux folks, By mistake I built `XFRM_ESP` into the Linux kernel, resulting in CONFIG_CRYPTO_SEQIV=y CONFIG_CRYPTO_ECHAINIV=y and also the Jitterentropy RNG to be built in. CRYPTO_JITTERENTROPY=y So, on the Asus F2A85-M PRO starting Linux 4.10-rc3 with `initcall_debug`, the init method is run unconditionally, and it takes 17.5 ms, which is over ten percent of the overall 900 ms the Linux kernel needs until loading the init process. [ 0.300544] calling jent_mod_init+0x0/0x2c @ 1 [ 0.318438] initcall jent_mod_init+0x0/0x2c returned 0 after 17471 usecs Looking at the output of systemd-bootchart, it looks like, that this indeed delayed the boot a little, as the other init methods seem to be ordered after it. I am now building it as a module, but am wondering if the time can be reduced to below ten milliseconds. Kind regards, Paul