From patchwork Mon Jun 12 09:07:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13276144 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 BB703C8300C for ; Mon, 12 Jun 2023 09:56:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234565AbjFLJ4v (ORCPT ); Mon, 12 Jun 2023 05:56:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232365AbjFLJyV (ORCPT ); Mon, 12 Jun 2023 05:54:21 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B634D4C05; Mon, 12 Jun 2023 02:38:56 -0700 (PDT) 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=8IwM37e642EshGkaM591nsICKeU24b96IU4dYucK72I=; b=dXBEmpz80b7hoderM45846w/8O pNO8hpipMKRJ27niZQqDP/oZ7/BF1rbJvgcP4PNZOjA0/uy51im9efmFnxUQeqkaz8ERUeIMTVgbA 4VU+/qmkIVh9mruK1Kemd08wt+2YvNqj7iMBDIb55yjZBxdNbyYHd4vmkglhIRzn3VhbsO1g6kMNX DPownbe5F7lKMEY9oMSiQbAsQ6Sq/LDRo6BH7dsjs/eLhKCTZkfWMRYDFaavzf9aNxmS0+JA4YiOd d6r7PI/eGL4W69GpFhaxW3FPhqLQIpOokWmypJbsZsB0KhQzPHHjPZBSmrvaJDXXl2NqdZOvB1M89 9hb3DItQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1q8e0g-008kPD-1r; Mon, 12 Jun 2023 09:38:51 +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 226E43031CC; Mon, 12 Jun 2023 11:38:49 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 5D3FD30A77B5B; Mon, 12 Jun 2023 11:38:48 +0200 (CEST) Message-ID: <20230612093538.792690687@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:07:31 +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 18/57] sched: Simplify sched_rr_get_interval() 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 | 40 ++++++++++++++++------------------------ 1 file changed, 16 insertions(+), 24 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8941,38 +8941,30 @@ SYSCALL_DEFINE1(sched_get_priority_min, static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) { - struct task_struct *p; - unsigned int time_slice; - struct rq_flags rf; - struct rq *rq; + unsigned int time_slice = 0; int retval; if (pid < 0) return -EINVAL; - retval = -ESRCH; - rcu_read_lock(); - p = find_process_by_pid(pid); - if (!p) - goto out_unlock; - - retval = security_task_getscheduler(p); - if (retval) - goto out_unlock; - - rq = task_rq_lock(p, &rf); - time_slice = 0; - if (p->sched_class->get_rr_interval) - time_slice = p->sched_class->get_rr_interval(rq, p); - task_rq_unlock(rq, p, &rf); + scoped_guard (rcu) { + struct task_struct *p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (retval) + return retval; + + scoped_guard (task_rq_lock, p) { + struct rq *rq = scope.rq; + if (p->sched_class->get_rr_interval) + time_slice = p->sched_class->get_rr_interval(rq, p); + } + } - rcu_read_unlock(); jiffies_to_timespec64(time_slice, t); return 0; - -out_unlock: - rcu_read_unlock(); - return retval; } /**