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 2D57FC43334 for ; Wed, 8 Jun 2022 15:11:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243622AbiFHPLE (ORCPT ); Wed, 8 Jun 2022 11:11:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243371AbiFHPK2 (ORCPT ); Wed, 8 Jun 2022 11:10:28 -0400 Received: from mail-yb1-f172.google.com (mail-yb1-f172.google.com [209.85.219.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E7F246F8CE; Wed, 8 Jun 2022 08:01:17 -0700 (PDT) Received: by mail-yb1-f172.google.com with SMTP id p13so36971739ybm.1; Wed, 08 Jun 2022 08:01:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=hna+hKCo48NcMl7Pqd/5P+UyLOQ1wF88gpvnodTJhxE=; b=vlsS08/X13NCCoVNEOmpS71IBzxKuXi6flyI8AcfeeYWsWD/ztcSRvgl1Tsni97Fy7 QkEhN0mLSgYJExsGaITnwHmGMoJthSziLUAba15/TlVhwC0WhNa8iwkY73lsmZswROuH +rhfgX9pypo4uV64UijL45J0Vl1i7Bd5JwzJ9zmGe2dhVbX1R2TspTSOoBF8X76teXzP 8DNuV0KCXQkfzCij5+Ql9h0CAcKGVtM/LasWL7HuJ3KnbdIBov/OJA3wsuhpF4kEi+O9 B4j9EJcvnQFU8w/px8Yzrwfj6ANa8tovdUPwQw+iA+7DLshQ10g3yBCGplqsYtzR8cDQ AAgg== X-Gm-Message-State: AOAM531jyaKTiKqRuT/tZdlg/N2S+bqehl07TxqGkenAdsyYkENSg+31 ebj5j+EjBeNzNHUcDWoXex025nYdBQLWgNa6ZMU= X-Google-Smtp-Source: ABdhPJwqalQMdxMy/pZcDZhBH1xedB7nhZhOlo0yW6lp9BXwx4h5qG3Bba3YMzpLPF7jDA8EKVOjRHlndcGghrEojUg= X-Received: by 2002:a5b:4a:0:b0:663:7c5b:a5ba with SMTP id e10-20020a5b004a000000b006637c5ba5bamr16536948ybp.81.1654700476488; Wed, 08 Jun 2022 08:01:16 -0700 (PDT) MIME-Version: 1.0 References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> In-Reply-To: <20220608144516.172460444@infradead.org> From: "Rafael J. Wysocki" Date: Wed, 8 Jun 2022 17:01:05 +0200 Message-ID: Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE To: Peter Zijlstra Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, Russell King - ARM Linux , ulli.kroll@googlemail.com, Linus Walleij , Shawn Guo , Sascha Hauer , Sascha Hauer , Fabio Estevam , dl-linux-imx , Tony Lindgren , Kevin Hilman , Catalin Marinas , Will Deacon , Guo Ren , bcain@quicinc.com, Huacai Chen , kernel@xen0n.name, Geert Uytterhoeven , sammy@sammy.net, Michal Simek , Thomas Bogendoerfer , dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, Stafford Horne , James Bottomley , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Yoshinori Sato , Rich Felker , David Miller , Richard Weinberger , anton.ivanov@cambridgegreys.com, Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "the arch/x86 maintainers" , "H. Peter Anvin" , acme@kernel.org, Mark Rutland , Alexander Shishkin , jolsa@kernel.org, namhyung@kernel.org, Juergen Gross , srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, Boris Ostrovsky , chris@zankel.net, jcmvbkbc@gmail.com, "Rafael J. Wysocki" , Len Brown , Pavel Machek , Greg Kroah-Hartman , Michael Turquette , Stephen Boyd , Daniel Lezcano , lpieralisi@kernel.org, Sudeep Holla , Andy Gross , Bjorn Andersson , Anup Patel , Thierry Reding , Jon Hunter , Jacob Pan , Arnd Bergmann , Yury Norov , Andy Shevchenko , Rasmus Villemoes , Steven Rostedt , Petr Mladek , senozhatsky@chromium.org, John Ogness , "Paul E. McKenney" , Frederic Weisbecker , quic_neeraju@quicinc.com, Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Benjamin Segall , Mel Gorman , Daniel Bristot de Oliveira , vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, Linux Kernel Mailing List , linux-snps-arc@lists.infradead.org, Linux ARM , Linux OMAP Mailing List , linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k , "open list:BROADCOM NVRAM DRIVER" , openrisc@lists.librecores.org, Parisc List , linuxppc-dev , linux-riscv , linux-s390@vger.kernel.org, Linux-sh list , sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, ACPI Devel Maling List , Linux PM , linux-clk , linux-arm-msm , linux-tegra , linux-arch , rcu@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Wed, Jun 8, 2022 at 4:47 PM Peter Zijlstra wrote: > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > Xeons") wrecked intel_idle in two ways: > > - must not have tracing in idle functions > - must return with IRQs disabled > > Additionally, it added a branch for no good reason. > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > Signed-off-by: Peter Zijlstra (Intel) Acked-by: Rafael J. Wysocki And do I think correctly that this can be applied without the rest of the series? > --- > drivers/idle/intel_idle.c | 48 +++++++++++++++++++++++++++++++++++----------- > 1 file changed, 37 insertions(+), 11 deletions(-) > > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > * > * Must be called under local_irq_disable(). > */ > + > -static __cpuidle int intel_idle(struct cpuidle_device *dev, > - struct cpuidle_driver *drv, int index) > +static __always_inline int __intel_idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > { > struct cpuidle_state *state = &drv->states[index]; > unsigned long eax = flg2MWAIT(state->flags); > unsigned long ecx = 1; /* break on interrupt flag */ > > - if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) > - local_irq_enable(); > - > mwait_idle_with_hints(eax, ecx); > > return index; > } > > +static __cpuidle int intel_idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > +{ > + return __intel_idle(dev, drv, index); > +} > + > +static __cpuidle int intel_idle_irq(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > +{ > + int ret; > + > + raw_local_irq_enable(); > + ret = __intel_idle(dev, drv, index); > + raw_local_irq_disable(); > + > + return ret; > +} > + > /** > * intel_idle_s2idle - Ask the processor to enter the given idle state. > * @dev: cpuidle device of the target CPU. > @@ -1801,6 +1824,9 @@ static void __init intel_idle_init_cstat > /* Structure copy. */ > drv->states[drv->state_count] = cpuidle_state_table[cstate]; > > + if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE) > + drv->states[drv->state_count].enter = intel_idle_irq; > + > if ((disabled_states_mask & BIT(drv->state_count)) || > ((icpu->use_acpi || force_use_acpi) && > intel_idle_off_by_default(mwait_hint) && > >