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[23.128.96.18]) by mx.google.com with ESMTP id j17si2112292ejc.223.2020.06.04.13.55.10; Thu, 04 Jun 2020 13:55:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730139AbgFDUvn (ORCPT + 99 others); Thu, 4 Jun 2020 16:51:43 -0400 Received: from mga06.intel.com ([134.134.136.31]:46522 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729855AbgFDUvm (ORCPT ); Thu, 4 Jun 2020 16:51:42 -0400 IronPort-SDR: 5rLgl5+qO89McM0SHHgm2sv/I44a8qLqr0eIFVtK26LQLge7H3mgQhRKAZDHnAlKxWdYvVV4sc /PCMYwoAvBVA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2020 13:51:41 -0700 IronPort-SDR: zs+MMvxWw13sjlZ9Bw72P4E7fjGK2DTGpjrAZCIfDuEufJrPSBND+RoMuQFrepsdDPuoy+96Bf +AJaXGZ7wG6g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,472,1583222400"; d="scan'208";a="348215104" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by orsmga001.jf.intel.com with ESMTP; 04 Jun 2020 13:51:40 -0700 Date: Thu, 4 Jun 2020 13:51:40 -0700 From: Ira Weiny To: Mike Rapoport Cc: Guenter Roeck , Andrew Morton , linux-kernel@vger.kernel.org, Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Chris Zankel , Max Filippov , Dan Williams , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, dri-devel@lists.freedesktop.org, Christian Koenig , Al Viro , Christoph Hellwig Subject: Re: [PATCH] arch/{mips,sparc,microblaze,powerpc}: Don't enable pagefault/preempt twice Message-ID: <20200604205140.GN1505637@iweiny-DESK2.sc.intel.com> References: <20200519165422.GA5838@roeck-us.net> <20200519184031.GB3356843@iweiny-DESK2.sc.intel.com> <20200519194215.GA71941@roeck-us.net> <20200520051315.GA3660833@iweiny-DESK2.sc.intel.com> <20200521174250.GB176262@iweiny-DESK2.sc.intel.com> <20200603135736.e7b5ded0082a81ae6d9067a0@linux-foundation.org> <20200603211416.GA1740285@iweiny-DESK2.sc.intel.com> <3538c8ad-674e-d310-d870-4ef6888092ed@roeck-us.net> <20200604094133.GC202650@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200604094133.GC202650@kernel.org> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 04, 2020 at 12:41:33PM +0300, Mike Rapoport wrote: > On Wed, Jun 03, 2020 at 04:44:17PM -0700, Guenter Roeck wrote: > > > > sparc32 smp images in next-20200603 still crash for me with a spinlock > > recursion. s390 images hang early in boot. Several others (alpha, arm64, > > various ppc) don't even compile. I can run some more bisects over time, > > but this is becoming a full-time job :-(. > > I've been able to bisect s390 hang to commit b614345f52bc ("x86/entry: > Clarify irq_{enter,exit}_rcu()"). > > After this commit, lockdep_hardirq_exit() is called twice on s390 (and > others) - one time in irq_exit_rcu() and another one in irq_exit(): > > /** > * irq_exit_rcu() - Exit an interrupt context without updating RCU > * > * Also processes softirqs if needed and possible. > */ > void irq_exit_rcu(void) > { > __irq_exit_rcu(); > /* must be last! */ > lockdep_hardirq_exit(); > } > > /** > * irq_exit - Exit an interrupt context, update RCU and lockdep > * > * Also processes softirqs if needed and possible. > */ > void irq_exit(void) > { > irq_exit_rcu(); > rcu_irq_exit(); > /* must be last! */ > lockdep_hardirq_exit(); > } > > Removing the call in irq_exit() make s390 boot again, and judgung by the > x86 entry code, the comment /* must be last! */ is stale... FWIW I got s390 to compile and this patch fixes s390 booting for me as well. 13:05:25 > /home/iweiny/dev/linux-build-test/rootfs/s390/run-qemu-s390.sh Build reference: next-20200603-4-g840714292d8c Building s390:defconfig:initrd ... running ........... passed Building s390:defconfig:virtio-blk-ccw:rootfs ... running ........... passed Building s390:defconfig:scsi[virtio-ccw]:rootfs ... running .............. passed Building s390:defconfig:virtio-pci:rootfs ... running ........... passed Building s390:defconfig:scsi[virtio-pci]:rootfs ... running ........... passed Ira > > @Peter, @Thomas, can you comment please? > > From e51d50ee6f4d1f446decf91c2c67230da14ff82c Mon Sep 17 00:00:00 2001 > From: Mike Rapoport > Date: Thu, 4 Jun 2020 12:37:03 +0300 > Subject: [PATCH] softirq: don't call lockdep_hardirq_exit() twice > > After commit b614345f52bc ("x86/entry: Clarify irq_{enter,exit}_rcu()") > lockdep_hardirq_exit() is called twice on every architecture that uses > irq_exit(): one time in irq_exit_rcu() and another one in irq_exit(). > > Remove the extra call in irq_exit(). > > Signed-off-by: Mike Rapoport > --- > kernel/softirq.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/kernel/softirq.c b/kernel/softirq.c > index a3eb6eba8c41..7523f4ce4c1d 100644 > --- a/kernel/softirq.c > +++ b/kernel/softirq.c > @@ -427,7 +427,6 @@ static inline void __irq_exit_rcu(void) > void irq_exit_rcu(void) > { > __irq_exit_rcu(); > - /* must be last! */ > lockdep_hardirq_exit(); > } > > @@ -440,8 +439,6 @@ void irq_exit(void) > { > irq_exit_rcu(); > rcu_irq_exit(); > - /* must be last! */ > - lockdep_hardirq_exit(); > } > > /* > -- > 2.26.2 > > > > > Guenter > > -- > Sincerely yours, > Mike.