From nobody Mon Feb 9 03:10:55 2026 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2DE531C689D for ; Mon, 4 Nov 2024 13:57:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730728622; cv=none; b=ojLHuNpzLGzLlDH1XpFmtFCMCehfTjzOo54OT2QogUe8Q2s92qpQXzHjomt2qiZhmkc50ssKeq0j5GJ/JDnbqyG+UIYuHEanKUfer7Nppz8TKCMOQulAAgZtCCNONG6ygENle7Xbss0fqdlWi1l3mYmGHVGcsfQiFm89AG7tigk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730728622; c=relaxed/simple; bh=s8LfhPT+pLCmBo0f4JA+CkTH/zWwnsVN5ObiFgKyaaE=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=lwq7+jO8RKSEcEppj8MDWuxDHJl8FKi5IxFqAvFj9+1SokW/+N65DyCWpMicL0ulwI0EsDIG7i+Ln19iCVTErHB7S2seMJr3n5//QJVUDWhQwlRMoJ+oskXFT9zw1BEjMhN4tAF4/7AjGx/4SO73I/b+Mnvlw+v4cglYZIQirRI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=O/AR8zW3; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="O/AR8zW3" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=O9KexFLcBrR17VmEpNmv6Paedf/C3oA4xrEmGRfDEUo=; b=O/AR8zW33EqVcxZmaNXnPkzkHf 2+gsgoKcAWizq1z4LAppeiiY5zrU2AqDS0WtRlJQHIYKLnWmGIGTsT1W5Iwb7GmI/DZykymE+PAcS CgocaLvyAXA/DfJx/7c4Gae+2Ma8CblTZf8NozyDfE+LRUiu8i5WTjg1H441BDsmHgrVEUTe3fysV /X+eN49uCuHHfyK1z0PctUyjQ+1muujTWfqBOeiFVQiTxEyeU8n2G7PxUZmj4pk2xipBoqCehh4Wn MaPmWkmvmsSyXBQozGu1vy0PTO8inmgpPRS+AJUBMMvM2sS+JMciPpBnYgYaUKg+cyAL9mYR0n3Zb lbdgeb+A==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t7xZX-00000001EDs-1GsS; Mon, 04 Nov 2024 13:56:48 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 63496302DF7; Mon, 4 Nov 2024 14:56:46 +0100 (CET) Message-Id: <20241104135518.090915501@infradead.org> User-Agent: quilt/0.65 Date: Mon, 04 Nov 2024 14:39:14 +0100 From: Peter Zijlstra To: mingo@kernel.org, lucas.demarchi@intel.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, willy@infradead.org, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com Subject: [PATCH 05/19] perf: Simplify perf_pmu_register() error path References: <20241104133909.669111662@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The error path of perf_pmu_register() is of course very similar to a subset of perf_pmu_unregister(). Extract this common part in perf_pmu_free() and simplify things. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 66 ++++++++++++++++++++++------------------------= ----- 1 file changed, 29 insertions(+), 37 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11540,11 +11540,6 @@ static int perf_event_idx_default(struct return 0; } =20 -static void free_pmu_context(struct pmu *pmu) -{ - free_percpu(pmu->cpu_pmu_context); -} - /* * Let userspace know that this PMU supports address range filtering: */ @@ -11771,25 +11766,38 @@ static bool idr_cmpxchg(struct idr *idr, return true; } =20 +static void perf_pmu_free(struct pmu *pmu) +{ + free_percpu(pmu->pmu_disable_count); + if (pmu_bus_running && pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { + if (pmu->nr_addr_filters) + device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); + device_del(pmu->dev); + put_device(pmu->dev); + } + free_percpu(pmu->cpu_pmu_context); +} + int perf_pmu_register(struct pmu *pmu, const char *name, int type) { int cpu, ret, max =3D PERF_TYPE_MAX; =20 + pmu->type =3D -1; + mutex_lock(&pmus_lock); ret =3D -ENOMEM; pmu->pmu_disable_count =3D alloc_percpu(int); if (!pmu->pmu_disable_count) goto unlock; =20 - pmu->type =3D -1; if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) { ret =3D -EINVAL; - goto free_pdc; + goto free; } =20 if (WARN_ONCE(pmu->scope >=3D PERF_PMU_MAX_SCOPE, "Can not register a pmu= with an invalid scope.\n")) { ret =3D -EINVAL; - goto free_pdc; + goto free; } =20 pmu->name =3D name; @@ -11799,24 +11807,23 @@ int perf_pmu_register(struct pmu *pmu, c =20 ret =3D idr_alloc(&pmu_idr, NULL, max, 0, GFP_KERNEL); if (ret < 0) - goto free_pdc; + goto free; =20 WARN_ON(type >=3D 0 && ret !=3D type); =20 - type =3D ret; - pmu->type =3D type; + pmu->type =3D ret; atomic_set(&pmu->exclusive_cnt, 0); =20 if (pmu_bus_running && !pmu->dev) { ret =3D pmu_dev_alloc(pmu); if (ret) - goto free_idr; + goto free; } =20 ret =3D -ENOMEM; pmu->cpu_pmu_context =3D alloc_percpu(struct perf_cpu_pmu_context); if (!pmu->cpu_pmu_context) - goto free_dev; + goto free; =20 for_each_possible_cpu(cpu) { struct perf_cpu_pmu_context *cpc; @@ -11857,8 +11864,10 @@ int perf_pmu_register(struct pmu *pmu, c /* * Now that the PMU is complete, make it visible to perf_try_init_event(). */ - if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) - goto free_context; + if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) { + ret =3D -EINVAL; + goto free; + } list_add_rcu(&pmu->entry, &pmus); =20 ret =3D 0; @@ -11867,20 +11876,10 @@ int perf_pmu_register(struct pmu *pmu, c =20 return ret; =20 -free_context: - free_percpu(pmu->cpu_pmu_context); - -free_dev: - if (pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { - device_del(pmu->dev); - put_device(pmu->dev); - } - -free_idr: - idr_remove(&pmu_idr, pmu->type); - -free_pdc: - free_percpu(pmu->pmu_disable_count); +free: + if (pmu->type >=3D 0) + idr_remove(&pmu_idr, pmu->type); + perf_pmu_free(pmu); goto unlock; } EXPORT_SYMBOL_GPL(perf_pmu_register); @@ -11899,14 +11898,7 @@ void perf_pmu_unregister(struct pmu *pmu synchronize_srcu(&pmus_srcu); synchronize_rcu(); =20 - free_percpu(pmu->pmu_disable_count); - if (pmu_bus_running && pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { - if (pmu->nr_addr_filters) - device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); - device_del(pmu->dev); - put_device(pmu->dev); - } - free_pmu_context(pmu); + perf_pmu_free(pmu); } EXPORT_SYMBOL_GPL(perf_pmu_unregister);