From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752784AbaHKFcn (ORCPT ); Mon, 11 Aug 2014 01:32:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:49446 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752547AbaHKFcl (ORCPT ); Mon, 11 Aug 2014 01:32:41 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,839,1400050800"; d="scan'208";a="556698908" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Robert Richter , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , kan.liang@intel.com, Alexander Shishkin Subject: [PATCH v3 19/23] perf: Add a helper for looking up pmus by type Date: Mon, 11 Aug 2014 08:19:48 +0300 Message-Id: <1407734392-31097-20-git-send-email-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1407734392-31097-1-git-send-email-alexander.shishkin@linux.intel.com> References: <1407734392-31097-1-git-send-email-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 d4b5e33b74..c0f05f8748 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6831,6 +6831,18 @@ void perf_pmu_unregister(struct pmu *pmu) } EXPORT_SYMBOL_GPL(perf_pmu_unregister); +/* 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; +} + struct pmu *perf_init_event(struct perf_event *event) { struct pmu *pmu = NULL; @@ -6839,9 +6851,7 @@ 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) { if (!try_module_get(pmu->module)) { pmu = ERR_PTR(-ENODEV); -- 2.1.0.rc1