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=-2.3 required=3.0 tests=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 7559DC4CEC9 for ; Tue, 17 Sep 2019 17:32:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AF412171F for ; Tue, 17 Sep 2019 17:32:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731175AbfIQRct (ORCPT ); Tue, 17 Sep 2019 13:32:49 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:47204 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726060AbfIQRct (ORCPT ); Tue, 17 Sep 2019 13:32:49 -0400 Received: (from willy@localhost) by pcw.home.local (8.15.2/8.15.2/Submit) id x8HHWPHL028048; Tue, 17 Sep 2019 19:32:25 +0200 Date: Tue, 17 Sep 2019 19:32:25 +0200 From: Willy Tarreau To: Lennart Poettering Cc: "Alexander E. Patrakov" , Linus Torvalds , Matthew Garrett , "Ahmed S. Darwish" , "Theodore Y. Ts'o" , Vito Caputo , Andreas Dilger , Jan Kara , Ray Strode , William Jon McCann , zhangjs , linux-ext4@vger.kernel.org, lkml Subject: Re: Linux 5.3-rc8 Message-ID: <20190917173225.GE27999@1wt.eu> References: <20190917052438.GA26923@1wt.eu> <2508489.jOnZlRuxVn@merkaba> <6ae36cda-5045-6873-9727-1d36bf45b84e@gmail.com> <20190917173036.GC31798@gardel-login> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190917173036.GC31798@gardel-login> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Archived-At: List-Archive: List-Post: On Tue, Sep 17, 2019 at 07:30:36PM +0200, Lennart Poettering wrote: > On Di, 17.09.19 21:58, Alexander E. Patrakov (patrakov@gmail.com) wrote: > > > I am worried that the getrandom delays will be serialized, because processes > > sometimes run one after another. If there are enough chained/dependent > > processes that ask for randomness before it is ready, the end result is > > still a too-big delay, essentially a failed boot. > > > > In other words: your approach of adding delays only makes sense for heavily > > parallelized boot, which may not be the case, especially for embedded > > systems that don't like systemd. > > As mentioned elsewhere: once the pool is initialized it's > initialized. This means any pending getrandom() on the whole system > will unblock at the same time, and from the on all getrandom()s will > be non-blocking. He means that all process will experience this delay until there's enough entropy. Willy