From patchwork Mon Jun 12 09:07:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13276164 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 12F0EC7EE2E for ; Mon, 12 Jun 2023 09:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235421AbjFLJ5i (ORCPT ); Mon, 12 Jun 2023 05:57:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233804AbjFLJys (ORCPT ); Mon, 12 Jun 2023 05:54:48 -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 07AB14C18; Mon, 12 Jun 2023 02:39:14 -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=ICqqJG5l0sWCX8xrZRxbU0jefpCN2MYfe0yl/+VCRM4=; b=CKNAf/OLveGu3h4G35M1XEIV5u NBuElad+1Cyz7hAjxLmdiofAlNZ59WVXwN3CrP9Gfl4Ccdi/+VZXviefm9IV8ZOsEiIAALkH+ZQeM JSCshvWoOk2ye0l3PailK5L7O/HIe+rzqBLavcMqSUulNXyI0lqc5mlQE1RAC+EzaqyQPBUzKfid5 LYfkCZS8vnyRr2VmNLRD6E8uxxm0Qg99fQqc78oc6Bz3sD5VsR472rJ6vx1URMn7VGFn0WBGdm0KG /Q43F20jOaH5vDTomYkIeci0EFi5Mfq3RUVPKf9bOojvjiudIa4EFwja6+7exCspONRew6SwRyHT0 wI+FO4zQ==; 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 1q8e0n-008kR8-1I; Mon, 12 Jun 2023 09:39:04 +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 3F98B3033B5; Mon, 12 Jun 2023 11:38:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id CA60630A77B6F; Mon, 12 Jun 2023 11:38:48 +0200 (CEST) Message-ID: <20230612093540.181605463@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:07:50 +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 37/57] perf: Simplify perf_read_group() References: <20230612090713.652690195@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5472,11 +5472,10 @@ static int perf_read_group(struct perf_e struct perf_event *leader = event->group_leader, *child; struct perf_event_context *ctx = leader->ctx; int ret; - u64 *values; lockdep_assert_held(&ctx->mutex); - values = kzalloc(event->read_size, GFP_KERNEL); + u64 *values __free(kfree) = kzalloc(event->read_size, GFP_KERNEL); if (!values) return -ENOMEM; @@ -5486,29 +5485,22 @@ static int perf_read_group(struct perf_e * By locking the child_mutex of the leader we effectively * lock the child list of all siblings.. XXX explain how. */ - mutex_lock(&leader->child_mutex); - - ret = __perf_read_group_add(leader, read_format, values); - if (ret) - goto unlock; - - list_for_each_entry(child, &leader->child_list, child_list) { - ret = __perf_read_group_add(child, read_format, values); + scoped_guard (mutex, &leader->child_mutex) { + ret = __perf_read_group_add(leader, read_format, values); if (ret) - goto unlock; - } + return ret; - mutex_unlock(&leader->child_mutex); + list_for_each_entry(child, &leader->child_list, child_list) { + ret = __perf_read_group_add(child, read_format, values); + if (ret) + return ret; + } + } ret = event->read_size; if (copy_to_user(buf, values, event->read_size)) - ret = -EFAULT; - goto out; + return -EFAULT; -unlock: - mutex_unlock(&leader->child_mutex); -out: - kfree(values); return ret; }