From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759512AbcIWLay (ORCPT ); Fri, 23 Sep 2016 07:30:54 -0400 Received: from mga03.intel.com ([134.134.136.65]:40735 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759300AbcIWL36 (ORCPT ); Fri, 23 Sep 2016 07:29:58 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,381,1470726000"; d="scan'208";a="172354490" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, vince@deater.net, eranian@google.com, Arnaldo Carvalho de Melo , tglx@linutronix.de, ak@linux.intel.com, Alexander Shishkin Subject: [RFC PATCH 3/6] perf: Add a helper for looking up pmus by type Date: Fri, 23 Sep 2016 14:27:23 +0300 Message-Id: <20160923112726.5890-4-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160923112726.5890-1-alexander.shishkin@linux.intel.com> References: <20160923112726.5890-1-alexander.shishkin@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds a helper for looking up a registered pmu by its type. Signed-off-by: Alexander Shishkin --- kernel/events/core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 2e8a0e389b..b64a5c611f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8780,6 +8780,18 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) return ret; } +/* call under pmus_srcu */ +static struct pmu *__perf_find_pmu(u32 type) +{ + struct pmu *pmu; + + rcu_read_lock(); + pmu = idr_find(&pmu_idr, type); + rcu_read_unlock(); + + return pmu; +} + static struct pmu *perf_init_event(struct perf_event *event) { struct pmu *pmu = NULL; @@ -8788,9 +8800,7 @@ static struct pmu *perf_init_event(struct perf_event *event) idx = srcu_read_lock(&pmus_srcu); - rcu_read_lock(); - pmu = idr_find(&pmu_idr, event->attr.type); - rcu_read_unlock(); + pmu = __perf_find_pmu(event->attr.type); if (pmu) { ret = perf_try_init_event(pmu, event); if (ret) -- 2.9.3