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Mon, 12 Jun 2023 11:38:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 0DD7E30A79080; Mon, 12 Jun 2023 11:38:49 +0200 (CEST) Message-ID: <20230612093540.931189374@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:08:00 +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 47/57] perf: Simplify perf_pmu_register() 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 | 40 ++++++++++++++++------------------------ 1 file changed, 16 insertions(+), 24 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11344,22 +11344,23 @@ void __perf_pmu_unregister(struct pmu *p free_pmu_context(pmu); } -int perf_pmu_register(struct pmu *pmu, const char *name, int type) +DEFINE_FREE(pmu_unregister, struct pmu *, if (_T) __perf_pmu_unregister(_T)) + +int perf_pmu_register(struct pmu *_pmu, const char *name, int type) { int cpu, ret, max = PERF_TYPE_MAX; - pmu->type = -1; + _pmu->type = -1; + + guard(mutex)(&pmus_lock); + struct pmu *pmu __free(pmu_unregister) = _pmu; - mutex_lock(&pmus_lock); - ret = -ENOMEM; pmu->pmu_disable_count = alloc_percpu(int); if (!pmu->pmu_disable_count) - goto unlock; + return -ENOMEM; - if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) { - ret = -EINVAL; - goto free; - } + if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) + return -EINVAL; pmu->name = name; @@ -11368,7 +11369,7 @@ int perf_pmu_register(struct pmu *pmu, c ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL); if (ret < 0) - goto free; + return ret; WARN_ON(type >= 0 && ret != type); @@ -11377,13 +11378,12 @@ int perf_pmu_register(struct pmu *pmu, c if (pmu_bus_running && !pmu->dev) { ret = pmu_dev_alloc(pmu); if (ret) - goto free; + return ret; } - ret = -ENOMEM; pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context); if (!pmu->cpu_pmu_context) - goto free; + return -ENOMEM; for_each_possible_cpu(cpu) { struct perf_cpu_pmu_context *cpc; @@ -11423,21 +11423,14 @@ int perf_pmu_register(struct pmu *pmu, c list_add_rcu(&pmu->entry, &pmus); atomic_set(&pmu->exclusive_cnt, 0); - ret = 0; -unlock: - mutex_unlock(&pmus_lock); - - return ret; - -free: - __perf_pmu_unregister(pmu); - goto unlock; + no_free_ptr(pmu); // let it rip + return 0; } EXPORT_SYMBOL_GPL(perf_pmu_register); void perf_pmu_unregister(struct pmu *pmu) { - mutex_lock(&pmus_lock); + guard(mutex)(&pmus_lock); list_del_rcu(&pmu->entry); /* @@ -11448,7 +11441,6 @@ void perf_pmu_unregister(struct pmu *pmu synchronize_rcu(); __perf_pmu_unregister(pmu); - mutex_unlock(&pmus_lock); } EXPORT_SYMBOL_GPL(perf_pmu_unregister);