From patchwork Mon Jun 12 09:07:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13276171 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 71EB2C7EE43 for ; Mon, 12 Jun 2023 09:58:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235987AbjFLJ6E (ORCPT ); Mon, 12 Jun 2023 05:58:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232091AbjFLJyX (ORCPT ); Mon, 12 Jun 2023 05:54:23 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B5204C10; Mon, 12 Jun 2023 02:38:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=i7e4Ed2VApizqqMeLDQrTIcscOdlMDKi2d1+AvdLSfc=; b=wMzEZ40Omey0hsxhU/f3YtsHn5 zztcNlN85LbTkIssyfkfrL48NmxnO6Xui7xALjewqMlyvd6RZfe6D4fBUEzU8ivSmkwH/rB+mgo8T DhIJ64bXK4MQAZHj4XNZbgTg99syxZL71a1nSxvAdXCC6Uq6WFU3Xo8Qau8qLevXW3vCcNOlO2hGd kLRb3QAfPguHrywS9Q4UgqR5mxOfj+Fk/M4IRihmVpaRZyf1EnKiw6p0zeUoZx/4h4dCUGPxRMpDH XqqMxcqWisvIc3MeLjMSkQ+D+XHT/6tgpmqY6cFvXD2CLwtL8aPDEHRB9Vg3FRPnxzDUV9pZfUiAM GAqscdag==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1q8e0g-002N94-7B; Mon, 12 Jun 2023 09:38:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A9B5B302FB8; Mon, 12 Jun 2023 11:38:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 22F9530A70248; Mon, 12 Jun 2023 11:38:48 +0200 (CEST) Message-ID: <20230612093537.977924652@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:07:21 +0200 From: Peter Zijlstra To: torvalds@linux-foundation.org, keescook@chromium.org, gregkh@linuxfoundation.org, pbonzini@redhat.com Cc: masahiroy@kernel.org, nathan@kernel.org, ndesaulniers@google.com, nicolas@fjasle.eu, catalin.marinas@arm.com, will@kernel.org, vkoul@kernel.org, trix@redhat.com, ojeda@kernel.org, peterz@infradead.org, mingo@redhat.com, longman@redhat.com, boqun.feng@gmail.com, dennis@kernel.org, tj@kernel.org, cl@linux.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, joel@joelfernandes.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, rientjes@google.com, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, apw@canonical.com, joe@perches.com, dwaipayanray1@gmail.com, lukas.bulwahn@gmail.com, john.johansen@canonical.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, llvm@lists.linux.dev, linux-perf-users@vger.kernel.org, rcu@vger.kernel.org, linux-security-module@vger.kernel.org, tglx@linutronix.de, ravi.bangoria@amd.com, error27@gmail.com, luc.vanoostenryck@gmail.com Subject: [PATCH v3 08/57] sched: Simplify wake_up_if_idle() References: <20230612090713.652690195@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Use guards to reduce gotos and simplify control flow. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/core.c | 20 ++++++-------------- kernel/sched/sched.h | 15 +++++++++++++++ 2 files changed, 21 insertions(+), 14 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3872,21 +3872,13 @@ static void __ttwu_queue_wakelist(struct void wake_up_if_idle(int cpu) { struct rq *rq = cpu_rq(cpu); - struct rq_flags rf; - rcu_read_lock(); - - if (!is_idle_task(rcu_dereference(rq->curr))) - goto out; - - rq_lock_irqsave(rq, &rf); - if (is_idle_task(rq->curr)) - resched_curr(rq); - /* Else CPU is not idle, do nothing here: */ - rq_unlock_irqrestore(rq, &rf); - -out: - rcu_read_unlock(); + guard(rcu)(); + if (is_idle_task(rcu_dereference(rq->curr))) { + guard(rq_lock)(rq); + if (is_idle_task(rq->curr)) + resched_curr(rq); + } } bool cpus_share_cache(int this_cpu, int that_cpu) --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1678,6 +1678,21 @@ rq_unlock(struct rq *rq, struct rq_flags raw_spin_rq_unlock(rq); } +DEFINE_LOCK_GUARD_1(rq_lock, struct rq, + rq_lock(_T->lock, &_T->rf), + rq_unlock(_T->lock, &_T->rf), + struct rq_flags rf) + +DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq, + rq_lock_irq(_T->lock, &_T->rf), + rq_unlock_irq(_T->lock, &_T->rf), + struct rq_flags rf) + +DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, + rq_lock_irqsave(_T->lock, &_T->rf), + rq_unlock_irqrestore(_T->lock, &_T->rf), + struct rq_flags rf) + static inline struct rq * this_rq_lock_irq(struct rq_flags *rf) __acquires(rq->lock)