From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751549AbeCNRLK (ORCPT ); Wed, 14 Mar 2018 13:11:10 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:51804 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbeCNRLJ (ORCPT ); Wed, 14 Mar 2018 13:11:09 -0400 Date: Wed, 14 Mar 2018 18:11:06 +0100 (CET) From: Thomas Gleixner To: Mark Rutland cc: Marc Zyngier , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jason Cooper , Grzegorz Jaszczyk Subject: Re: [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds In-Reply-To: <20180314165708.daoui66waxvicciq@lakrids.cambridge.arm.com> Message-ID: References: <20180313172103.24281-1-marc.zyngier@arm.com> <20180313175156.gmncij4rnqcdl5ie@lakrids.cambridge.arm.com> <72c7a6d2-a4c4-26b2-2982-c1d1ffb39b81@arm.com> <20180314165708.daoui66waxvicciq@lakrids.cambridge.arm.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 14 Mar 2018, Mark Rutland wrote: > On Tue, Mar 13, 2018 at 06:35:07PM +0000, Marc Zyngier wrote: > > On 13/03/18 17:51, Mark Rutland wrote: > > > On Tue, Mar 13, 2018 at 05:21:00PM +0000, Marc Zyngier wrote: > > >> As kexec and kdump are getting used a bit more intensively, I've been > > >> made aware of a number of shortcomings. > > >> > > >> The main gripe is from folks trying to launch a kdump kernel from > > >> within an interrupt handler. If using EOImode==1, things work as > > >> expected. If using EOImode==0 (such as in a guest), the secondary > > >> kernel hangs as the previous interrupt hasn't been EOI'd, and the > > >> active priority is still set. The first two patches are addressing > > >> this situation for both GICv2 and GICv3 by reseting the APRs to their > > >> default value. > > > > > > As a more general thing, if irqchip drivers have state that needs to be > > > reset in their init code, can we live all this irqchip reset to the > > > crashdump kernel, and kill machine_kexec_mask_interrupts() entirely? > > > > We could, once we know for sure that all the potential irqchips have > > been fixed. Or we could just remove it immediately, and see what breaks. > > I would be very tempted to do the latter. Makes sense. Do we have any indicator that tells us that a particular irq chip is missing something in the init code or do we have to rely on crash reports? Thanks, tglx