From patchwork Tue Sep 6 07:46:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 666356 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3sSzZl0Kmzz9s9c for ; Tue, 6 Sep 2016 18:01:51 +1000 (AEST) Received: from localhost ([::1]:59728 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhBKF-0005TC-U9 for incoming@patchwork.ozlabs.org; Tue, 06 Sep 2016 04:01:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38884) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhB6O-0001Jg-6U for qemu-devel@nongnu.org; Tue, 06 Sep 2016 03:47:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bhB6F-0002CG-Mf for qemu-devel@nongnu.org; Tue, 06 Sep 2016 03:47:27 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55570) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhB6F-0002C4-DN for qemu-devel@nongnu.org; Tue, 06 Sep 2016 03:47:19 -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 u867gSkr069015 for ; Tue, 6 Sep 2016 03:47:18 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 259r1mvdtu-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 06 Sep 2016 03:47:18 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 6 Sep 2016 08:47:14 +0100 X-IBM-Helo: d06dlp01.portsmouth.uk.ibm.com X-IBM-MailFrom: cornelia.huck@de.ibm.com X-IBM-RcptTo: qemu-devel@nongnu.org Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 45D5A17D8067 for ; Tue, 6 Sep 2016 08:49:06 +0100 (BST) Received: from d06av06.portsmouth.uk.ibm.com (d06av06.portsmouth.uk.ibm.com [9.149.37.217]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u867lECJ25100520 for ; Tue, 6 Sep 2016 07:47:14 GMT Received: from d06av06.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u867lDt9013363 for ; Tue, 6 Sep 2016 03:47:14 -0400 Received: from gondolin.boeblingen.de.ibm.com (dyn-9-152-224-137.boeblingen.de.ibm.com [9.152.224.137]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u867lCmR013216 (version=TLSv1/SSLv3 cipher=AES256-SHA256 bits=256 verify=NO); Tue, 6 Sep 2016 03:47:13 -0400 From: Cornelia Huck To: peter.maydell@linaro.org Date: Tue, 6 Sep 2016 09:46:36 +0200 X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160906074710.13495-1-cornelia.huck@de.ibm.com> References: <20160906074710.13495-1-cornelia.huck@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16090607-0008-0000-0000-000002BE90D6 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16090607-0009-0000-0000-000019B391F0 Message-Id: <20160906074710.13495-5-cornelia.huck@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-09-06_03:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1609060120 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PULL 04/38] s390/sclp: cache the sclp device X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cornelia Huck , borntraeger@de.ibm.com, jfrei@linux.vnet.ibm.com, agraf@suse.de, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Christian Borntraeger With the current code a simple sclp command takes about 13000 ns The biggest part seems to be the resolver of the object model. By caching the sclp device the time for an sclp command goes down to 2500ns. Talking about real life scenarios, this change doubles the speed of the sclp console when sending single bytes outputs to /dev/console. Signed-off-by: Christian Borntraeger Reviewed-by: Cornelia Huck Signed-off-by: Cornelia Huck --- hw/s390x/sclp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c index fca37f5..540226c 100644 --- a/hw/s390x/sclp.c +++ b/hw/s390x/sclp.c @@ -26,7 +26,12 @@ static inline SCLPDevice *get_sclp_device(void) { - return SCLP(object_resolve_path_type("", TYPE_SCLP, NULL)); + static SCLPDevice *sclp; + + if (!sclp) { + sclp = SCLP(object_resolve_path_type("", TYPE_SCLP, NULL)); + } + return sclp; } /* Provide information about the configuration, CPUs and storage */