From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755000AbaDRNWW (ORCPT ); Fri, 18 Apr 2014 09:22:22 -0400 Received: from terminus.zytor.com ([198.137.202.10]:38859 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754397AbaDRNJH (ORCPT ); Fri, 18 Apr 2014 09:09:07 -0400 Date: Fri, 18 Apr 2014 06:08:19 -0700 From: "tip-bot for Yan, Zheng" Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, acme@kernel.org, zheng.z.yan@intel.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, acme@kernel.org, zheng.z.yan@intel.com, tglx@linutronix.de In-Reply-To: <1395133004-23205-1-git-send-email-zheng.z.yan@intel.com> References: <1395133004-23205-1-git-send-email-zheng.z.yan@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf: Allow building PMU drivers as modules Git-Commit-ID: c464c76eec4be587604ca082e8cded7e6b89f3bf X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c464c76eec4be587604ca082e8cded7e6b89f3bf Gitweb: http://git.kernel.org/tip/c464c76eec4be587604ca082e8cded7e6b89f3bf Author: Yan, Zheng AuthorDate: Tue, 18 Mar 2014 16:56:41 +0800 Committer: Ingo Molnar CommitDate: Fri, 18 Apr 2014 12:54:45 +0200 perf: Allow building PMU drivers as modules This patch adds support for building PMU driver as module. It exports the functions perf_pmu_{register,unregister}() and adds reference tracking for the PMU driver module. When the PMU driver is built as a module, each active event of the PMU holds a reference to the driver module. Signed-off-by: Yan, Zheng Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1395133004-23205-1-git-send-email-zheng.z.yan@intel.com Cc: eranian@google.com Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + kernel/events/core.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 3356abc..af6dcf1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -172,6 +172,7 @@ struct perf_event; struct pmu { struct list_head entry; + struct module *module; struct device *dev; const struct attribute_group **attr_groups; const char *name; diff --git a/kernel/events/core.c b/kernel/events/core.c index f83a71a..5129b12 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -39,6 +39,7 @@ #include #include #include +#include #include "internal.h" @@ -3229,6 +3230,9 @@ static void __free_event(struct perf_event *event) if (event->ctx) put_ctx(event->ctx); + if (event->pmu) + module_put(event->pmu->module); + call_rcu(&event->rcu_head, free_event_rcu); } static void free_event(struct perf_event *event) @@ -6551,6 +6555,7 @@ free_pdc: free_percpu(pmu->pmu_disable_count); goto unlock; } +EXPORT_SYMBOL_GPL(perf_pmu_register); void perf_pmu_unregister(struct pmu *pmu) { @@ -6572,6 +6577,7 @@ void perf_pmu_unregister(struct pmu *pmu) put_device(pmu->dev); free_pmu_context(pmu); } +EXPORT_SYMBOL_GPL(perf_pmu_unregister); struct pmu *perf_init_event(struct perf_event *event) { @@ -6585,6 +6591,10 @@ struct pmu *perf_init_event(struct perf_event *event) pmu = idr_find(&pmu_idr, event->attr.type); rcu_read_unlock(); if (pmu) { + if (!try_module_get(pmu->module)) { + pmu = ERR_PTR(-ENODEV); + goto unlock; + } event->pmu = pmu; ret = pmu->event_init(event); if (ret) @@ -6593,6 +6603,10 @@ struct pmu *perf_init_event(struct perf_event *event) } list_for_each_entry_rcu(pmu, &pmus, entry) { + if (!try_module_get(pmu->module)) { + pmu = ERR_PTR(-ENODEV); + goto unlock; + } event->pmu = pmu; ret = pmu->event_init(event); if (!ret) @@ -6771,6 +6785,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, err_pmu: if (event->destroy) event->destroy(event); + module_put(pmu->module); err_ns: if (event->ns) put_pid_ns(event->ns);