From patchwork Thu Sep 29 15:51:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 9356653 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 543F86077B for ; Thu, 29 Sep 2016 15:50:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41E44285C7 for ; Thu, 29 Sep 2016 15:50:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3105429BB1; Thu, 29 Sep 2016 15:50:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6F52D285C7 for ; Thu, 29 Sep 2016 15:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934011AbcI2Pux (ORCPT ); Thu, 29 Sep 2016 11:50:53 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49706 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933968AbcI2Puv (ORCPT ); Thu, 29 Sep 2016 11:50:51 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u8TFmtNF081518 for ; Thu, 29 Sep 2016 11:50:51 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 25s33m12sb-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 29 Sep 2016 11:50:50 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 29 Sep 2016 16:50:47 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 36A2D1B08023; Thu, 29 Sep 2016 16:52:42 +0100 (BST) Received: from d06av11.portsmouth.uk.ibm.com (d06av11.portsmouth.uk.ibm.com [9.149.37.252]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u8TFolNG66388146; Thu, 29 Sep 2016 15:50:47 GMT Received: from d06av11.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u8TFoiLE006760; Thu, 29 Sep 2016 09:50:46 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u8TFoiOO006738 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 29 Sep 2016 09:50:44 -0600 Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id 8682120F1E3; Thu, 29 Sep 2016 17:50:44 +0200 (CEST) From: Christian Borntraeger To: Peter Zijlstra , Martin Schwidefsky , Heiko Carstens Cc: 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, Christian Borntraeger Subject: [PATCH v2 1/1] s390/spinlock: Provide vcpu_is_preempted Date: Thu, 29 Sep 2016 17:51:05 +0200 X-Mailer: git-send-email 2.5.5 In-Reply-To: <1475164265-246160-1-git-send-email-borntraeger@de.ibm.com> References: <1475164265-246160-1-git-send-email-borntraeger@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16092915-0028-0000-0000-000002266394 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16092915-0029-0000-0000-000020A14C47 Message-Id: <1475164265-246160-2-git-send-email-borntraeger@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-09-29_10:, , 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=8.0.1-1609020000 definitions=main-1609290277 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- arch/s390/include/asm/spinlock.h | 3 +++ arch/s390/kernel/smp.c | 9 +++++++-- arch/s390/lib/spinlock.c | 25 ++++++++----------------- 3 files changed, 18 insertions(+), 19 deletions(-) diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 63ebf37..e16e02f 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -21,6 +21,9 @@ _raw_compare_and_swap(unsigned int *lock, unsigned int old, unsigned int new) return __sync_bool_compare_and_swap(lock, old, new); } +bool arch_vcpu_is_preempted(int cpu); +#define vcpu_is_preempted arch_vcpu_is_preempted + /* * Simple spin lock operations. There are two variants, one clears IRQ's * on the local processor, one does not. diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 7b89a75..4aadd16 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -376,10 +376,15 @@ int smp_find_processor_id(u16 address) return -1; } -int smp_vcpu_scheduled(int cpu) +bool arch_vcpu_is_preempted(int cpu) { - return pcpu_running(pcpu_devices + cpu); + if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) + return false; + if (pcpu_running(pcpu_devices + cpu)) + return false; + return true; } +EXPORT_SYMBOL(arch_vcpu_is_preempted); void smp_yield_cpu(int cpu) { diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index e5f50a7..e48a48e 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -37,15 +37,6 @@ static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old) asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock)); } -static inline int cpu_is_preempted(int cpu) -{ - if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) - return 0; - if (smp_vcpu_scheduled(cpu)) - return 0; - return 1; -} - void arch_spin_lock_wait(arch_spinlock_t *lp) { unsigned int cpu = SPINLOCK_LOCKVAL; @@ -62,7 +53,7 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) continue; } /* First iteration: check if the lock owner is running. */ - if (first_diag && cpu_is_preempted(~owner)) { + if (first_diag && arch_vcpu_is_preempted(~owner)) { smp_yield_cpu(~owner); first_diag = 0; continue; @@ -81,7 +72,7 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) * yield the CPU unconditionally. For LPAR rely on the * sense running status. */ - if (!MACHINE_IS_LPAR || cpu_is_preempted(~owner)) { + if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) { smp_yield_cpu(~owner); first_diag = 0; } @@ -108,7 +99,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) continue; } /* Check if the lock owner is running. */ - if (first_diag && cpu_is_preempted(~owner)) { + if (first_diag && arch_vcpu_is_preempted(~owner)) { smp_yield_cpu(~owner); first_diag = 0; continue; @@ -127,7 +118,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) * yield the CPU unconditionally. For LPAR rely on the * sense running status. */ - if (!MACHINE_IS_LPAR || cpu_is_preempted(~owner)) { + if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) { smp_yield_cpu(~owner); first_diag = 0; } @@ -165,7 +156,7 @@ void _raw_read_lock_wait(arch_rwlock_t *rw) owner = 0; while (1) { if (count-- <= 0) { - if (owner && cpu_is_preempted(~owner)) + if (owner && arch_vcpu_is_preempted(~owner)) smp_yield_cpu(~owner); count = spin_retry; } @@ -211,7 +202,7 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev) owner = 0; while (1) { if (count-- <= 0) { - if (owner && cpu_is_preempted(~owner)) + if (owner && arch_vcpu_is_preempted(~owner)) smp_yield_cpu(~owner); count = spin_retry; } @@ -241,7 +232,7 @@ void _raw_write_lock_wait(arch_rwlock_t *rw) owner = 0; while (1) { if (count-- <= 0) { - if (owner && cpu_is_preempted(~owner)) + if (owner && arch_vcpu_is_preempted(~owner)) smp_yield_cpu(~owner); count = spin_retry; } @@ -285,7 +276,7 @@ void arch_lock_relax(unsigned int cpu) { if (!cpu) return; - if (MACHINE_IS_LPAR && !cpu_is_preempted(~cpu)) + if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(~cpu)) return; smp_yield_cpu(~cpu); }