From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-rt-users-owner@vger.kernel.org Received: from mout.gmx.net ([212.227.17.21]:53023 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730764AbeGZTKF (ORCPT ); Thu, 26 Jul 2018 15:10:05 -0400 Message-ID: <1532627521.6124.13.camel@gmx.de> Subject: Re: [rfc 4.16-rt patch] arm64: efi,fpsimd: use a local_lock() in efi_virtmap_load() From: Mike Galbraith Date: Thu, 26 Jul 2018 19:52:01 +0200 In-Reply-To: <20180726150934.tsrk6kgc2nmhbxq2@linutronix.de> References: <1531321642.12761.30.camel@gmx.de> <20180726150934.tsrk6kgc2nmhbxq2@linutronix.de> Content-Type: text/plain; charset="ISO-8859-15" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-rt-users-owner@vger.kernel.org List-ID: To: Sebastian Andrzej Siewior Cc: linux-rt-users , Thomas Gleixner , Steven Rostedt On Thu, 2018-07-26 at 17:09 +0200, Sebastian Andrzej Siewior wrote: > On 2018-07-11 17:07:22 [+0200], Mike Galbraith wrote: > > Greetings, > > > > With the patch below, there's still one neon splat to figure out what > > to do with should this patch not die a gruesome death. Cavium box > > boots and seemingly works fine modulo kvm, which is utterly deadly in > > 4.16-rt due to.. > > > > 972 if (!vgic_initialized(vcpu->kvm)) > > 973 return false; > > 974 > > 975 irq = vgic_get_irq(vcpu->kvm, vcpu, vintid); > > 976 spin_lock_irqsave(&irq->irq_lock, flags); > > > > ..that lock apparently having wandered into a minefield post v4.14. > > > > Remaining neon splat: > > I don't have this with preempt-disable patch for kernel_neon_begin() > (posted seconds ago). Oh, forget you _ever saw_ that patch. It later demonstrated it's "correctness" quite convincingly. I didn't explicitly recall it due to the patch it tried to build upon proving in the end to be a bit south of wonderful itself, making the whole exercise a "let's make a bad situation even worse" kinda thing :) -Mike