From patchwork Wed Dec 7 12:41:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li RongQing X-Patchwork-Id: 632829 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 7F51AC352A1 for ; Wed, 7 Dec 2022 12:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229797AbiLGMma (ORCPT ); Wed, 7 Dec 2022 07:42:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229674AbiLGMm2 (ORCPT ); Wed, 7 Dec 2022 07:42:28 -0500 Received: from bddwd-sys-mailin01.bddwd.baidu.com (mx402.baidu.com [124.64.201.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C6E76391C2; Wed, 7 Dec 2022 04:42:27 -0800 (PST) Received: from bjhw-sys-rpm015653cc5.bjhw.baidu.com (bjhw-sys-rpm015653cc5.bjhw.baidu.com [10.227.53.39]) by bddwd-sys-mailin01.bddwd.baidu.com (Postfix) with ESMTP id 6087A11980033; Wed, 7 Dec 2022 20:41:35 +0800 (CST) Received: from localhost (localhost [127.0.0.1]) by bjhw-sys-rpm015653cc5.bjhw.baidu.com (Postfix) with ESMTP id 59702D9932; Wed, 7 Dec 2022 20:41:35 +0800 (CST) From: lirongqing@baidu.com To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, rafael@kernel.org, daniel.lezcano@linaro.org, peterz@infradead.org, akpm@linux-foundation.org, tony.luck@intel.com, jpoimboe@kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH 1/2][v2] cpuidle-haltpoll: Replace default_idle with arch_cpu_idle Date: Wed, 7 Dec 2022 20:41:34 +0800 Message-Id: <1670416895-50172-1-git-send-email-lirongqing@baidu.com> X-Mailer: git-send-email 1.7.1 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Li RongQing When KVM guest has MWAIT and mwait_idle is used as default idle function, but once cpuidle-haltpoll is loaded, default_idle in default_enter_idle is used, which is using HLT, and cause a performance regression. As the commit aebef63cf7ff ("x86: Remove vendor checks from prefer_mwait_c1_over_halt") explains that mwait is preferred so replace default_idle with arch_cpu_idle which can using MWAIT optimization. latency of sockperf ping-pong localhost test is reduced by more 20% unixbench has 5% performance improvements for single core Suggested-by: Thomas Gleixner Suggested-by: Rafael J. Wysocki Signed-off-by: Li RongQing --- arch/x86/kernel/process.c | 1 + drivers/cpuidle/cpuidle-haltpoll.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c21b734..303afad 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -721,6 +721,7 @@ void arch_cpu_idle(void) { x86_idle(); } +EXPORT_SYMBOL(arch_cpu_idle); /* * We use this if we don't have any better idle routine.. diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c index 3a39a7f..e66df22 100644 --- a/drivers/cpuidle/cpuidle-haltpoll.c +++ b/drivers/cpuidle/cpuidle-haltpoll.c @@ -32,7 +32,7 @@ static int default_enter_idle(struct cpuidle_device *dev, local_irq_enable(); return index; } - default_idle(); + arch_cpu_idle(); return index; }