From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DB96C197A0 for ; Mon, 20 Nov 2023 15:16:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234463AbjKTPQt (ORCPT ); Mon, 20 Nov 2023 10:16:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234364AbjKTPQe (ORCPT ); Mon, 20 Nov 2023 10:16:34 -0500 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3503BE; Mon, 20 Nov 2023 07:16:30 -0800 (PST) Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3AKF2Z4M005926; Mon, 20 Nov 2023 15:15:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2023-03-30; bh=uAhbu4AUajdcQROPp7AvbiHI/LFlFhMVo6VGoxnZCWM=; b=iWm+eqFDXMPL5yZeVVivDaYQytpZR3S/mzy8etq05l2MOlypXUEQv/NlVT9fec+oMhtz n6qGjTv90sWy1upsgg/PIzkJFQu1Etcu5jo+g8rKD0xSjrOf6pp7oYpwgoQ5MNF6zwWE 93OErUMGMZPhTtsrGMiM9TKbrZX2/fJxDJJ+12ujXGEaMvovc4UR2YbMvmPljXeynlgd 01PhAiRt0XeHp/KUnWYeru74ECbsdn8TbZs5c2MMwCk548yK80dpJR+BLulGzaV7+Ana 5a267z8ctt3NaKeDhr4sotvF63M/mOGOM4eu8A41OfAhDxjbB9WiXrDaWWT6dfZkWymQ QA== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3uemvuava8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Nov 2023 15:15:25 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 3AKF2uu1023572; Mon, 20 Nov 2023 15:15:24 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3uekq5gr51-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Nov 2023 15:15:24 +0000 Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3AKFFF8d037000; Mon, 20 Nov 2023 15:15:24 GMT Received: from mihai.localdomain (ban25x6uut25.us.oracle.com [10.153.73.25]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3uekq5gqwc-8; Mon, 20 Nov 2023 15:15:23 +0000 From: Mihai Carabas To: linux-arm-kernel@lists.infradead.org Cc: kvm@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, pbonzini@redhat.com, wanpengli@tencent.com, vkuznets@redhat.com, rafael@kernel.org, daniel.lezcano@linaro.org, akpm@linux-foundation.org, pmladek@suse.com, peterz@infradead.org, dianders@chromium.org, npiggin@gmail.com, rick.p.edgecombe@intel.com, joao.m.martins@oracle.com, juerg.haefliger@canonical.com, mic@digikod.net, mihai.carabas@oracle.com, arnd@arndb.de, ankur.a.arora@oracle.com Subject: [PATCH 7/7] cpuidle/poll_state: replace cpu_relax with smp_cond_load_relaxed Date: Mon, 20 Nov 2023 16:01:38 +0200 Message-Id: <1700488898-12431-8-git-send-email-mihai.carabas@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1700488898-12431-1-git-send-email-mihai.carabas@oracle.com> References: <1700488898-12431-1-git-send-email-mihai.carabas@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-20_15,2023-11-20_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 suspectscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311200106 X-Proofpoint-GUID: nJCLzdI_KlVOa57CUYhmhyCxfgZd5UAK X-Proofpoint-ORIG-GUID: nJCLzdI_KlVOa57CUYhmhyCxfgZd5UAK Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org cpu_relax on ARM64 does a simple "yield". Thus we replace it with smp_cond_load_relaxed which basically does a "wfe". Suggested-by: Peter Zijlstra Signed-off-by: Mihai Carabas --- drivers/cpuidle/poll_state.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c index 9b6d90a72601..440cd713e39a 100644 --- a/drivers/cpuidle/poll_state.c +++ b/drivers/cpuidle/poll_state.c @@ -26,12 +26,16 @@ static int __cpuidle poll_idle(struct cpuidle_device *dev, limit = cpuidle_poll_time(drv, dev); - while (!need_resched()) { - cpu_relax(); - if (loop_count++ < POLL_IDLE_RELAX_COUNT) - continue; - + for (;;) { loop_count = 0; + + smp_cond_load_relaxed(¤t_thread_info()->flags, + (VAL & _TIF_NEED_RESCHED) || + (loop_count++ >= POLL_IDLE_RELAX_COUNT)); + + if (loop_count < POLL_IDLE_RELAX_COUNT) + break; + if (local_clock_noinstr() - time_start > limit) { dev->poll_time_limit = true; break; -- 1.8.3.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 29621C5AE5C for ; 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Mon, 20 Nov 2023 15:15:25 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 3AKF2uu1023572; Mon, 20 Nov 2023 15:15:24 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3uekq5gr51-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Nov 2023 15:15:24 +0000 Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3AKFFF8d037000; Mon, 20 Nov 2023 15:15:24 GMT Received: from mihai.localdomain (ban25x6uut25.us.oracle.com [10.153.73.25]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3uekq5gqwc-8; Mon, 20 Nov 2023 15:15:23 +0000 From: Mihai Carabas To: linux-arm-kernel@lists.infradead.org Cc: kvm@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, pbonzini@redhat.com, wanpengli@tencent.com, vkuznets@redhat.com, rafael@kernel.org, daniel.lezcano@linaro.org, akpm@linux-foundation.org, pmladek@suse.com, peterz@infradead.org, dianders@chromium.org, npiggin@gmail.com, rick.p.edgecombe@intel.com, joao.m.martins@oracle.com, juerg.haefliger@canonical.com, mic@digikod.net, mihai.carabas@oracle.com, arnd@arndb.de, ankur.a.arora@oracle.com Subject: [PATCH 7/7] cpuidle/poll_state: replace cpu_relax with smp_cond_load_relaxed Date: Mon, 20 Nov 2023 16:01:38 +0200 Message-Id: <1700488898-12431-8-git-send-email-mihai.carabas@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1700488898-12431-1-git-send-email-mihai.carabas@oracle.com> References: <1700488898-12431-1-git-send-email-mihai.carabas@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-20_15,2023-11-20_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 suspectscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311200106 X-Proofpoint-GUID: nJCLzdI_KlVOa57CUYhmhyCxfgZd5UAK X-Proofpoint-ORIG-GUID: nJCLzdI_KlVOa57CUYhmhyCxfgZd5UAK X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231120_071559_982799_AAB35C03 X-CRM114-Status: GOOD ( 16.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org cpu_relax on ARM64 does a simple "yield". Thus we replace it with smp_cond_load_relaxed which basically does a "wfe". Suggested-by: Peter Zijlstra Signed-off-by: Mihai Carabas --- drivers/cpuidle/poll_state.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c index 9b6d90a72601..440cd713e39a 100644 --- a/drivers/cpuidle/poll_state.c +++ b/drivers/cpuidle/poll_state.c @@ -26,12 +26,16 @@ static int __cpuidle poll_idle(struct cpuidle_device *dev, limit = cpuidle_poll_time(drv, dev); - while (!need_resched()) { - cpu_relax(); - if (loop_count++ < POLL_IDLE_RELAX_COUNT) - continue; - + for (;;) { loop_count = 0; + + smp_cond_load_relaxed(¤t_thread_info()->flags, + (VAL & _TIF_NEED_RESCHED) || + (loop_count++ >= POLL_IDLE_RELAX_COUNT)); + + if (loop_count < POLL_IDLE_RELAX_COUNT) + break; + if (local_clock_noinstr() - time_start > limit) { dev->poll_time_limit = true; break; -- 1.8.3.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel