From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 15/36] cpuidle,cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}() Date: Wed, 08 Jun 2022 16:27:38 +0200 Message-ID: <20220608144516.871305980@infradead.org> References: <20220608142723.103523089@infradead.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=fn1U7MEbZz2QK5hbMetRGs1LaJ4dLQ5TDl+y9fGIqjs=; b=AHoLDlFIJpM2yJSN34mWYuYDyZ RrXBAbCHcbiLETtqHyostv6hzGyHst5r7VORCZGrERmGvvRqMr2NwXjLQsK1TYGzVvVJBLCgsCf3j LieJtCZHAdjEyntbLFkbTU93xwC08IjFigevejKo+3rMPJ833Xxh7xrrmgzcKasuf6t3frm6PkmxU vZovY0XqO2YqPGD7SFjfk9rslAidePmYi7ReTaMHUlcVRH/amspREeDyWUmyOeqnEP6bQYjeAjWHS JBInW3LvF6tscP+ZjodqILQopYhhA13ptDRMV4kNqtb9FKzkYAPZG/ay8CNlYM5sVD+3xA6vTTC0E vR1dCMqg==; List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: peterz@infradead.org Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, ao All callers should still have RCU enabled. Signed-off-by: Peter Zijlstra (Intel) --- kernel/cpu_pm.c | 9 --------- 1 file changed, 9 deletions(-) --- a/kernel/cpu_pm.c +++ b/kernel/cpu_pm.c @@ -30,16 +30,9 @@ static int cpu_pm_notify(enum cpu_pm_eve { int ret; - /* - * This introduces a RCU read critical section, which could be - * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know - * this. - */ - rcu_irq_enter_irqson(); rcu_read_lock(); ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL); rcu_read_unlock(); - rcu_irq_exit_irqson(); return notifier_to_errno(ret); } @@ -49,11 +42,9 @@ static int cpu_pm_notify_robust(enum cpu unsigned long flags; int ret; - rcu_irq_enter_irqson(); raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags); ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL); raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags); - rcu_irq_exit_irqson(); return notifier_to_errno(ret); }