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 EAFA3C433EF for ; Wed, 8 Jun 2022 22:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=aveKzjt4isaxpWjdKstUEwCNZT3mmTB/1/wuiiCOJck=; b=LnxJQjjihTMRFr l+OEXJ3+Gi4oj2+swRIIms6ZLY2fenVVaA1Ocy9GRsw1JWHdXFSw6bi1TpFxn5RyLavN78mOiOQ/w vQqOK2NUVnz9gzuaFQ4lgA/Bqlp6In0jE1ZdtEj/6dTGzqFEdNX4+17bAWKfYlss2gFNDqRAYkrJY lECVPkNTlYsTXLdIdiVBJfgcFIDsIdbGJ3buc2OO32XgwtoaqdmX5FSFMp8z3G2LK+cgND300oLB4 N9QjQC0+Ip4XVCnO68tElRRcT2Ft7p0ItyXL0TCAsRAagwYPOYca7F+A15XAxuuCtNCZEtzM9PSe7 mkCG4kP1iE+n9WFaGwhA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nz3lX-00F6LI-CB; Wed, 08 Jun 2022 22:03:03 +0000 Received: from mail-yb1-f171.google.com ([209.85.219.171]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nz0BG-00EeFF-92; Wed, 08 Jun 2022 18:13:24 +0000 Received: by mail-yb1-f171.google.com with SMTP id a30so19111012ybj.3; Wed, 08 Jun 2022 11:13:19 -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=ZQePx5uIM1fUidMEiJVM5nuB6ZzPVeEu38qEpc1UrpE=; b=tg22o8Q/s+6stDEGR8EH0wckuEs22loupRsSsi+4UrJnJG8SpiAcYzGFmxUDsffltA r3wLIVe/kdv1LNcAIOyIrfK21ZUKTdJ+Jz5YqrFn4vTWnTqTEV5nJQgm4ruQYSQgAJtF VKYBkm1WV7+Sv5CYdLY2ieB8qv+LWY5KPK1GBv9xTBMolloUtlJh+oz/dNl3738BRZJM Ba2zfBJh6M+vPpiAYkSAbSOuVKkhjwcijitMsosCq+Nn0lF+1CSQMfq+xFjqncmqdmCt +dgTqem0qnK+nW5IZq+8k133+JdEXWD7PXdYB/IcjCw5AMGYf0CzEMtKuWbAEfDa7kZ1 OB+w== X-Gm-Message-State: AOAM532iGM6MSC+Mb5ORdQIyrQ5YoSoUnXzzpMgrOMvgcAfmuQdA9zla lBWmwjTauPFgEiwcH8UjI9iZbNyWe6zeIfpNzss= X-Google-Smtp-Source: ABdhPJyd1CrHem+vVK3IGyX/t5xH0MretwaFF4fsfRB0Td7tNKI/Gb3F1VH58WOF1ULS3yEBVcV2AFovGma6uhuJi5U= X-Received: by 2002:a5b:4a:0:b0:663:7c5b:a5ba with SMTP id e10-20020a5b004a000000b006637c5ba5bamr17352131ybp.81.1654711998678; Wed, 08 Jun 2022 11:13:18 -0700 (PDT) MIME-Version: 1.0 References: <20220608142723.103523089@infradead.org> <20220608144516.047149313@infradead.org> In-Reply-To: <20220608144516.047149313@infradead.org> From: "Rafael J. Wysocki" Date: Wed, 8 Jun 2022 20:13:07 +0200 Message-ID: Subject: Re: [PATCH 02/36] x86/idle: Replace x86_idle with a static_call 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220608_111322_374926_435BA7CB X-CRM114-Status: GOOD ( 25.62 ) X-Mailman-Approved-At: Wed, 08 Jun 2022 15:02:58 -0700 X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Wed, Jun 8, 2022 at 4:47 PM Peter Zijlstra wrote: > > Typical boot time setup; no need to suffer an indirect call for that. > > Signed-off-by: Peter Zijlstra (Intel) > Reviewed-by: Frederic Weisbecker Reviewed-by: Rafael J. Wysocki > --- > arch/x86/kernel/process.c | 50 +++++++++++++++++++++++++--------------------- > 1 file changed, 28 insertions(+), 22 deletions(-) > > --- a/arch/x86/kernel/process.c > +++ b/arch/x86/kernel/process.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -692,7 +693,23 @@ void __switch_to_xtra(struct task_struct > unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; > EXPORT_SYMBOL(boot_option_idle_override); > > -static void (*x86_idle)(void); > +/* > + * We use this if we don't have any better idle routine.. > + */ > +void __cpuidle default_idle(void) > +{ > + raw_safe_halt(); > +} > +#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE) > +EXPORT_SYMBOL(default_idle); > +#endif > + > +DEFINE_STATIC_CALL_NULL(x86_idle, default_idle); > + > +static bool x86_idle_set(void) > +{ > + return !!static_call_query(x86_idle); > +} > > #ifndef CONFIG_SMP > static inline void play_dead(void) > @@ -715,28 +732,17 @@ void arch_cpu_idle_dead(void) > /* > * Called from the generic idle code. > */ > -void arch_cpu_idle(void) > -{ > - x86_idle(); > -} > - > -/* > - * We use this if we don't have any better idle routine.. > - */ > -void __cpuidle default_idle(void) > +void __cpuidle arch_cpu_idle(void) > { > - raw_safe_halt(); > + static_call(x86_idle)(); > } > -#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE) > -EXPORT_SYMBOL(default_idle); > -#endif > > #ifdef CONFIG_XEN > bool xen_set_default_idle(void) > { > - bool ret = !!x86_idle; > + bool ret = x86_idle_set(); > > - x86_idle = default_idle; > + static_call_update(x86_idle, default_idle); > > return ret; > } > @@ -859,20 +865,20 @@ void select_idle_routine(const struct cp > if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1) > pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n"); > #endif > - if (x86_idle || boot_option_idle_override == IDLE_POLL) > + if (x86_idle_set() || boot_option_idle_override == IDLE_POLL) > return; > > if (boot_cpu_has_bug(X86_BUG_AMD_E400)) { > pr_info("using AMD E400 aware idle routine\n"); > - x86_idle = amd_e400_idle; > + static_call_update(x86_idle, amd_e400_idle); > } else if (prefer_mwait_c1_over_halt(c)) { > pr_info("using mwait in idle threads\n"); > - x86_idle = mwait_idle; > + static_call_update(x86_idle, mwait_idle); > } else if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { > pr_info("using TDX aware idle routine\n"); > - x86_idle = tdx_safe_halt; > + static_call_update(x86_idle, tdx_safe_halt); > } else > - x86_idle = default_idle; > + static_call_update(x86_idle, default_idle); > } > > void amd_e400_c1e_apic_setup(void) > @@ -925,7 +931,7 @@ static int __init idle_setup(char *str) > * To continue to load the CPU idle driver, don't touch > * the boot_option_idle_override. > */ > - x86_idle = default_idle; > + static_call_update(x86_idle, default_idle); > boot_option_idle_override = IDLE_HALT; > } else if (!strcmp(str, "nomwait")) { > /* > > _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv