From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S946150AbcJSQS6 (ORCPT ); Wed, 19 Oct 2016 12:18:58 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58150 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935048AbcJSOSA (ORCPT ); Wed, 19 Oct 2016 10:18:00 -0400 Date: Wed, 19 Oct 2016 09:44:48 +0200 From: Heiko Carstens To: Christian Borntraeger Cc: Peter Zijlstra , Martin Schwidefsky , Pan Xinhui , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, xen-devel-request@lists.xenproject.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, mingo@redhat.com, paulmck@linux.vnet.ibm.com, will.deacon@arm.com, kernellwp@gmail.com, jgross@suse.com, pbonzini@redhat.com, bsingharora@gmail.com Subject: Re: [PATCH v2 1/1] s390/spinlock: Provide vcpu_is_preempted References: <1475164265-246160-1-git-send-email-borntraeger@de.ibm.com> <1475164265-246160-2-git-send-email-borntraeger@de.ibm.com> <190cd825-ca7c-d160-a0ac-4e0d27ac4a93@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <190cd825-ca7c-d160-a0ac-4e0d27ac4a93@de.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16101907-0040-0000-0000-00000248E6A3 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16101907-0041-0000-0000-000022394066 Message-Id: <20161019074448.GC4077@osiris> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-10-19_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1610190139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 19, 2016 at 08:56:36AM +0200, Christian Borntraeger wrote: > On 09/29/2016 05:51 PM, Christian Borntraeger wrote: > > this implements the s390 backend for commit > > "kernel/sched: introduce vcpu preempted check interface" > > by reworking the existing smp_vcpu_scheduled into > > arch_vcpu_is_preempted. We can then also get rid of the > > local cpu_is_preempted function by moving the > > CIF_ENABLED_WAIT test into arch_vcpu_is_preempted. > > > > Signed-off-by: Christian Borntraeger > > > Martin, Peter, > > I think we could go with the patch as is. In other words not providing > arch_vcpu_is_preempted for !CONFIG_SMP. > > This will result in compile errors if code does spinning or yielding for > non-SMP kernels - which does not make sense to me, so this might actually > be a nice indicator. > If you prefer the !CONFIG_SMP implementation let me know and I will respin. ...but I do prefer an implementation for !CONFIG_SMP. I'm tired of fixing silly compile errors that only happen on s390.