From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w8Msv4GzWzDqL3 for ; Fri, 21 Apr 2017 14:18:11 +1000 (AEST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3L4E78A143424 for ; Fri, 21 Apr 2017 00:18:06 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0b-001b2d01.pphosted.com with ESMTP id 29xxfapaf3-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 21 Apr 2017 00:18:06 -0400 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 21 Apr 2017 00:18:04 -0400 Date: Thu, 20 Apr 2017 21:17:54 -0700 From: "Paul E. McKenney" To: Michael Ellerman Cc: Paolo Bonzini , tglx@linutronix.de, kvm@vger.kernel.org, oleg@redhat.com, peterz@infradead.org, fweisbec@gmail.com, bobby.prani@gmail.com, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, josh@joshtriplett.org, dhowells@redhat.com, edumazet@google.com, "paulus@samba.org" , rostedt@goodmis.org, dipankar@in.ibm.com, mathieu.desnoyers@efficios.com, akpm@linux-foundation.org, "linuxppc-dev@lists.ozlabs.org" , mingo@kernel.org Subject: Re: powerpc KVM build break in linux-next (was Re: [PATCH tip/core/rcu 40/40] srcu: Parallelize callback handling) Reply-To: paulmck@linux.vnet.ibm.com References: <20170412174003.GA23207@linux.vnet.ibm.com> <1492018825-25634-40-git-send-email-paulmck@linux.vnet.ibm.com> <871ssn692a.fsf@concordia.ellerman.id.au> <24c85d26-bb4b-892d-5837-6d02af570e0e@redhat.com> <20170421003834.GA14351@linux.vnet.ibm.com> <87zifatu3a.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <87zifatu3a.fsf@concordia.ellerman.id.au> Message-Id: <20170421041754.GV3956@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Apr 21, 2017 at 11:42:01AM +1000, Michael Ellerman wrote: > "Paul E. McKenney" writes: > > On Thu, Apr 20, 2017 at 05:28:32PM +0200, Paolo Bonzini wrote: > >> On 20/04/2017 05:40, Michael Ellerman wrote: > >> > "Paul E. McKenney" writes: > >> > > >> > This change seems to have had the non-obvious effect of breaking the > >> > powerpc KVM build. > ... > >> > >> Michael, if you want to move the two srcu structs at the end of struct > >> kvm, that would be fine by me. Please send a patch yourself so you can > >> test it on PPC. Thanks, > > > > On the off-chance that it is at all helpful, I have added the commit > > shown below to -rcu. > > As shown below :) > > > If it helps, I am happy to push this, but am just as happy to drop it > > in favor of some other fix. If at all possible, I would like to get > > this into the upcoming merge window. > > Thanks, this looks perfect to me, and if you're happy to put it on top > of your tree that would limit the breakage to a smaller history window, > so that would be ideal. > > Tested-by: Michael Ellerman Thank you, Michael! Paolo, does this look good to you? My upstream maintainer will be much more likely to take this with your ack. ;-) Thanx, Paul > cheers > > > >From a19a6617e2817e485ccc2f7cc5a97bd7ff769b87 Mon Sep 17 00:00:00 2001 > From: "Paul E. McKenney" > Date: Thu, 20 Apr 2017 17:30:06 -0700 > Subject: kvm: Move srcu_struct fields to end of struct kvm > > Parallelizing SRCU callback handling increased the size of srcu_struct, > which moved the kvm_arch field within the kvm struct out of reach of > powerpc's current assembly code, resulting in the following sort of > build error: > > arch/powerpc/kvm/book3s_hv_rmhandlers.S:617: Error: operand out of range (0x000000000000b328 is not between 0xffffffffffff8000 and 0x0000000000007fff) > > This commit moves the srcu_struct fields in the kvm structure to follow > the kvm_arch field, which again allows powerpc's assembly code to > reach it. > > Reported-by: Stephen Rothwell > Reported-by: Michael Ellerman > Reported-by: kbuild test robot > Suggested-by: Paolo Bonzini > Signed-off-by: Paul E. McKenney > --- > include/linux/kvm_host.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 2c14ad9..96c8e29 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -375,8 +375,6 @@ struct kvm { > struct mutex slots_lock; > struct mm_struct *mm; /* userspace tied to this vm */ > struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM]; > - struct srcu_struct srcu; > - struct srcu_struct irq_srcu; > struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; > > /* > @@ -429,6 +427,8 @@ struct kvm { > struct list_head devices; > struct dentry *debugfs_dentry; > struct kvm_stat_data **debugfs_stat_data; > + struct srcu_struct srcu; > + struct srcu_struct irq_srcu; > }; > > #define kvm_err(fmt, ...) \ > -- > cgit v1.1