From nobody Wed Dec 31 14:58:40 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDA6DC0018A for ; Thu, 2 Nov 2023 15:33:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376841AbjKBPdf (ORCPT ); Thu, 2 Nov 2023 11:33:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347645AbjKBPdL (ORCPT ); Thu, 2 Nov 2023 11:33:11 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D67C118B for ; Thu, 2 Nov 2023 08:32:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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; 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charset="utf-8" Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 54 ++++++++++++++++------------------------------= ----- 1 file changed, 17 insertions(+), 37 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4434,7 +4434,8 @@ static void __perf_event_read(void *info if (ctx->task && cpuctx->task_ctx !=3D ctx) return; =20 - raw_spin_lock(&ctx->lock); + guard(raw_spinlock)(&ctx->lock); + if (ctx->is_active & EVENT_TIME) { update_context_time(ctx); update_cgrp_time_from_event(event); @@ -4445,12 +4446,12 @@ static void __perf_event_read(void *info perf_event_update_sibling_time(event); =20 if (event->state !=3D PERF_EVENT_STATE_ACTIVE) - goto unlock; + return; =20 if (!data->group) { pmu->read(event); data->ret =3D 0; - goto unlock; + return; } =20 pmu->start_txn(pmu, PERF_PMU_TXN_READ); @@ -4468,9 +4469,6 @@ static void __perf_event_read(void *info } =20 data->ret =3D pmu->commit_txn(pmu); - -unlock: - raw_spin_unlock(&ctx->lock); } =20 static inline u64 perf_event_count(struct perf_event *event) @@ -4501,32 +4499,25 @@ static void calc_timer_values(struct per int perf_event_read_local(struct perf_event *event, u64 *value, u64 *enabled, u64 *running) { - unsigned long flags; int event_oncpu; int event_cpu; - int ret =3D 0; - /* * Disabling interrupts avoids all counter scheduling (context * switches, timer based rotation and IPIs). */ - local_irq_save(flags); + guard(irqsave)(); =20 /* * It must not be an event with inherit set, we cannot read * all child counters from atomic context. */ - if (event->attr.inherit) { - ret =3D -EOPNOTSUPP; - goto out; - } + if (event->attr.inherit) + return -EOPNOTSUPP; =20 /* If this is a per-task event, it must be for current */ if ((event->attach_state & PERF_ATTACH_TASK) && - event->hw.target !=3D current) { - ret =3D -EINVAL; - goto out; - } + event->hw.target !=3D current) + return -EINVAL; =20 /* * Get the event CPU numbers, and adjust them to local if the event is @@ -4537,16 +4528,12 @@ int perf_event_read_local(struct perf_ev =20 /* If this is a per-CPU event, it must be for this CPU */ if (!(event->attach_state & PERF_ATTACH_TASK) && - event_cpu !=3D smp_processor_id()) { - ret =3D -EINVAL; - goto out; - } + event_cpu !=3D smp_processor_id()) + return -EINVAL; =20 /* If this is a pinned event it must be running on this CPU */ - if (event->attr.pinned && event_oncpu !=3D smp_processor_id()) { - ret =3D -EBUSY; - goto out; - } + if (event->attr.pinned && event_oncpu !=3D smp_processor_id()) + return -EBUSY; =20 /* * If the event is currently on this CPU, its either a per-task event, @@ -4566,10 +4553,8 @@ int perf_event_read_local(struct perf_ev if (running) *running =3D __running; } -out: - local_irq_restore(flags); =20 - return ret; + return 0; } =20 static int perf_event_read(struct perf_event *event, bool group) @@ -4603,7 +4588,7 @@ static int perf_event_read(struct perf_e .ret =3D 0, }; =20 - preempt_disable(); + guard(preempt)(); event_cpu =3D __perf_event_read_cpu(event, event_cpu); =20 /* @@ -4617,19 +4602,15 @@ static int perf_event_read(struct perf_e * after this. */ (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); - preempt_enable(); ret =3D data.ret; =20 } else if (state =3D=3D PERF_EVENT_STATE_INACTIVE) { struct perf_event_context *ctx =3D event->ctx; - unsigned long flags; =20 - raw_spin_lock_irqsave(&ctx->lock, flags); + guard(raw_spinlock_irqsave)(&ctx->lock); state =3D event->state; - if (state !=3D PERF_EVENT_STATE_INACTIVE) { - raw_spin_unlock_irqrestore(&ctx->lock, flags); + if (state !=3D PERF_EVENT_STATE_INACTIVE) goto again; - } =20 /* * May read while context is not active (e.g., thread is @@ -4643,7 +4624,6 @@ static int perf_event_read(struct perf_e perf_event_update_time(event); if (group) perf_event_update_sibling_time(event); - raw_spin_unlock_irqrestore(&ctx->lock, flags); } =20 return ret;