From patchwork Mon Jun 12 09:07:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13276109 X-Patchwork-Delegate: paul@paul-moore.com 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 05CC5C7EE45 for ; Mon, 12 Jun 2023 09:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235957AbjFLJ5w (ORCPT ); Mon, 12 Jun 2023 05:57:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229454AbjFLJyb (ORCPT ); Mon, 12 Jun 2023 05:54:31 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55F1F6185; Mon, 12 Jun 2023 02:39:03 -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=IwZQFShSV/PIl8fTfPc9l4QCHQp32ssy80H3iz5Si2g=; b=n2QBRERGYOTGa4H4UfPiQMxml4 DlIa7Bh+E0wy752HUyfCxpdFro63TOC2IKp9jPE5GAfa1mJYpUhJg7mXGYIHTeDn9BySpGXGbyVd3 IwJesqbM7Wb3W3h6YpQgJKi2jBSkPrZDWblalKMV6HQ84Jsy2sFXbKyI8rcW+nAOW3dJ/b920m92P rah0RrnGqtwQsyYb1dXy9/e8D1odgIYC+fkV2EbyFFqvSqo9mCNLgutnfVUAg637Ma+mnkR77qzmE PZQFREWg0jB+r3RJ1GGStrlIluYtwark33oMb5t5WyJikLV3GNXnRWJf6oZ44tLapABjEhnCdDKM9 42/wgNSw==; 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 1q8e0l-002NBI-II; Mon, 12 Jun 2023 09:38:55 +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 23BBA303196; Mon, 12 Jun 2023 11:38:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 8C04B30A77B63; Mon, 12 Jun 2023 11:38:48 +0200 (CEST) Message-ID: <20230612093539.371360635@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:07:39 +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 26/57] perf: Simplify event_function*() References: <20230612090713.652690195@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: Use guards to reduce gotos and simplify control flow. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -214,6 +214,25 @@ struct event_function_struct { void *data; }; +typedef struct { + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; +} class_perf_ctx_lock_t; + +static inline void class_perf_ctx_lock_destructor(class_perf_ctx_lock_t *_T) +{ + if (_T->cpuctx) + perf_ctx_unlock(_T->cpuctx, _T->ctx); +} + +static inline class_perf_ctx_lock_t +class_perf_ctx_lock_constructor(struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + perf_ctx_lock(cpuctx, ctx); + return (class_perf_ctx_lock_t){ cpuctx, ctx }; +} + static int event_function(void *info) { struct event_function_struct *efs = info; @@ -224,17 +243,15 @@ static int event_function(void *info) int ret = 0; lockdep_assert_irqs_disabled(); + guard(perf_ctx_lock)(cpuctx, task_ctx); - perf_ctx_lock(cpuctx, task_ctx); /* * Since we do the IPI call without holding ctx->lock things can have * changed, double check we hit the task we set out to hit. */ if (ctx->task) { - if (ctx->task != current) { - ret = -ESRCH; - goto unlock; - } + if (ctx->task != current) + return -ESRCH; /* * We only use event_function_call() on established contexts, @@ -254,8 +271,6 @@ static int event_function(void *info) } efs->func(event, cpuctx, ctx, efs->data); -unlock: - perf_ctx_unlock(cpuctx, task_ctx); return ret; } @@ -329,11 +344,11 @@ static void event_function_local(struct task_ctx = ctx; } - perf_ctx_lock(cpuctx, task_ctx); + guard(perf_ctx_lock)(cpuctx, task_ctx); task = ctx->task; if (task == TASK_TOMBSTONE) - goto unlock; + return; if (task) { /* @@ -343,18 +358,16 @@ static void event_function_local(struct */ if (ctx->is_active) { if (WARN_ON_ONCE(task != current)) - goto unlock; + return; if (WARN_ON_ONCE(cpuctx->task_ctx != ctx)) - goto unlock; + return; } } else { WARN_ON_ONCE(&cpuctx->ctx != ctx); } func(event, cpuctx, ctx, data); -unlock: - perf_ctx_unlock(cpuctx, task_ctx); } #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\