Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753940AbdGUPJk (ORCPT ); Fri, 21 Jul 2017 11:09:40 -0400 Received: from mail-oi0-f67.google.com ([209.85.218.67]:37781 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751302AbdGUPJM (ORCPT ); Fri, 21 Jul 2017 11:09:12 -0400 MIME-Version: 1.0 In-Reply-To: <2787001.lEj6P09Sfm@tauon.chronox.de> References: <3910055.ntkqcq1Chb@positron.chronox.de> <5238256.jqB5BlnSCf@positron.chronox.de> <20170721030846.m2r3ix4s2modahsw@thunk.org> <2787001.lEj6P09Sfm@tauon.chronox.de> From: Arnd Bergmann Date: Fri, 21 Jul 2017 17:09:11 +0200 X-Google-Sender-Auth: zVZPvKhwncoDYs03DCyQJgJxs-o Message-ID: Subject: Re: [RFC PATCH v12 3/4] Linux Random Number Generator To: =?UTF-8?Q?Stephan_M=C3=BCller?= Cc: "Theodore Ts'o" , Greg Kroah-Hartman , "Jason A. Donenfeld" , linux-crypto@vger.kernel.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6LFBco5020575 Content-Length: 936 Lines: 25 On Fri, Jul 21, 2017 at 10:57 AM, Stephan Müller wrote: > Am Freitag, 21. Juli 2017, 05:08:47 CEST schrieb Theodore Ts'o: >> Um, the timer is the largest number of interrupts on my system. Compare: >> >> CPU0 CPU1 CPU2 CPU3 >> LOC: 6396552 6038865 6558646 6057102 Local timer interrupts >> >> with the number of disk related interrupts: >> >> 120: 21492 139284 40513 1705886 PCI-MSI 376832-edge >> ahci[0000:00:17.0] > > They seem to be not picked up with the add_interrupt_randomness function. On x86, the local APIC timer has some special handling in arch/x86/entry/entry_64.S that does not go through handle_irq_event(). I would assume that this is different when you boot with the "noapictimer" option and use the hpet clockevent instead. On other architectures, the timer interrupt is often handled as a regular IRQ as well. Arnd