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[2620:137:e000::1:20]) by mx.google.com with ESMTP id t75-20020a63784e000000b0051b7357bb0csi1225591pgc.32.2023.04.14.05.58.28; Fri, 14 Apr 2023 05:58:42 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=iyoBXxA7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229907AbjDNM5J (ORCPT + 99 others); Fri, 14 Apr 2023 08:57:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230098AbjDNM5G (ORCPT ); Fri, 14 Apr 2023 08:57:06 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FC9A5FDE for ; Fri, 14 Apr 2023 05:56:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681476980; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8MIchSc/IRBHqG8cQoqV4sLghuhrbfRz6nKRE2TruRs=; b=iyoBXxA7PZa3KHRyuYXJJGY5wpig8ZB1maTdfTUnZUwrXDibH9m2p5NFDBv//RUu3Cn8JE nUCXXdyw4urjCG+r31U5BO6tbcRDFOz+X5BZE3ua2sZGFP0u7ey7XuTetEBZnwI7I12itg tmfGqw/oCEikm+1iXrZ5NKDxygJBuQ0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-108-HizxkZDTNICfXSF6gf899w-1; Fri, 14 Apr 2023 08:56:17 -0400 X-MC-Unique: HizxkZDTNICfXSF6gf899w-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 81C1485530D; Fri, 14 Apr 2023 12:56:16 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.9.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id ADB80406AA66; Fri, 14 Apr 2023 12:56:09 +0000 (UTC) From: Wander Lairson Costa To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Will Deacon , Waiman Long , Boqun Feng , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , "Eric W. Biederman" , Wander Lairson Costa , Michael Ellerman , Brian Cain , Kefeng Wang , Oleg Nesterov , Andrew Morton , "Liam R. Howlett" , Christian Brauner , Vlastimil Babka , Andrei Vagin , Shakeel Butt , linux-kernel@vger.kernel.org (open list), linux-perf-users@vger.kernel.org (open list:PERFORMANCE EVENTS SUBSYSTEM) Subject: [PATCH v6 3/3] treewide: replace put_task_struct() witht the atomic safe version Date: Fri, 14 Apr 2023 09:55:29 -0300 Message-Id: <20230414125532.14958-4-wander@redhat.com> In-Reply-To: <20230414125532.14958-1-wander@redhat.com> References: <20230414125532.14958-1-wander@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1763156554928955710?= X-GMAIL-MSGID: =?utf-8?q?1763156554928955710?= In places where put_task_struct() is called in a non-sleepable context, we replace those calls by put_task_struct_atomic_safe(). These call sites were found by running internal regression tests and looking for warnings generated by put_task_might_resched(). Signed-off-by: Wander Lairson Costa Cc: Valentin Schneider --- kernel/events/core.c | 6 +++--- kernel/locking/rtmutex.c | 10 +++++----- kernel/sched/core.c | 6 +++--- kernel/sched/deadline.c | 16 ++++++++-------- kernel/sched/rt.c | 4 ++-- 5 files changed, 21 insertions(+), 21 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 435815d3be3f..8f823da02324 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1181,7 +1181,7 @@ static void put_ctx(struct perf_event_context *ctx) if (ctx->parent_ctx) put_ctx(ctx->parent_ctx); if (ctx->task && ctx->task != TASK_TOMBSTONE) - put_task_struct(ctx->task); + put_task_struct_atomic_safe(ctx->task); call_rcu(&ctx->rcu_head, free_ctx); } } @@ -13019,7 +13019,7 @@ static void perf_event_exit_task_context(struct task_struct *child) RCU_INIT_POINTER(child->perf_event_ctxp, NULL); put_ctx(child_ctx); /* cannot be last */ WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE); - put_task_struct(current); /* cannot be last */ + put_task_struct_atomic_safe(current); /* cannot be last */ clone_ctx = unclone_ctx(child_ctx); raw_spin_unlock_irq(&child_ctx->lock); @@ -13124,7 +13124,7 @@ void perf_event_free_task(struct task_struct *task) */ RCU_INIT_POINTER(task->perf_event_ctxp, NULL); WRITE_ONCE(ctx->task, TASK_TOMBSTONE); - put_task_struct(task); /* cannot be last */ + put_task_struct_atomic_safe(task); /* cannot be last */ raw_spin_unlock_irq(&ctx->lock); diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 728f434de2bb..3ecb8d6ae039 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -509,7 +509,7 @@ static __always_inline void rt_mutex_wake_up_q(struct rt_wake_q_head *wqh) { if (IS_ENABLED(CONFIG_PREEMPT_RT) && wqh->rtlock_task) { wake_up_state(wqh->rtlock_task, TASK_RTLOCK_WAIT); - put_task_struct(wqh->rtlock_task); + put_task_struct_atomic_safe(wqh->rtlock_task); wqh->rtlock_task = NULL; } @@ -649,7 +649,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, "task: %s (%d)\n", max_lock_depth, top_task->comm, task_pid_nr(top_task)); } - put_task_struct(task); + put_task_struct_atomic_safe(task); return -EDEADLK; } @@ -817,7 +817,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * No requeue[7] here. Just release @task [8] */ raw_spin_unlock(&task->pi_lock); - put_task_struct(task); + put_task_struct_atomic_safe(task); /* * [9] check_exit_conditions_3 protected by lock->wait_lock. @@ -886,7 +886,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, /* [8] Release the task */ raw_spin_unlock(&task->pi_lock); - put_task_struct(task); + put_task_struct_atomic_safe(task); /* * [9] check_exit_conditions_3 protected by lock->wait_lock. @@ -990,7 +990,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, out_unlock_pi: raw_spin_unlock_irq(&task->pi_lock); out_put_task: - put_task_struct(task); + put_task_struct_atomic_safe(task); return ret; } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0d18c3969f90..a4783f0c9f01 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1007,7 +1007,7 @@ void wake_up_q(struct wake_q_head *head) * the queueing in wake_q_add() so as not to miss wakeups. */ wake_up_process(task); - put_task_struct(task); + put_task_struct_atomic_safe(task); } } @@ -2528,7 +2528,7 @@ int push_cpu_stop(void *arg) raw_spin_rq_unlock(rq); raw_spin_unlock_irq(&p->pi_lock); - put_task_struct(p); + put_task_struct_atomic_safe(p); return 0; } @@ -9316,7 +9316,7 @@ static int __balance_push_cpu_stop(void *arg) rq_unlock(rq, &rf); raw_spin_unlock_irq(&p->pi_lock); - put_task_struct(p); + put_task_struct_atomic_safe(p); return 0; } diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 71b24371a6f7..0f8b8a490dc0 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -327,7 +327,7 @@ static void dl_change_utilization(struct task_struct *p, u64 new_bw) * so we are still safe. */ if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + put_task_struct_atomic_safe(p); } __sub_rq_bw(p->dl.dl_bw, &rq->dl); __add_rq_bw(new_bw, &rq->dl); @@ -467,7 +467,7 @@ static void task_contending(struct sched_dl_entity *dl_se, int flags) * so we are still safe. */ if (hrtimer_try_to_cancel(&dl_se->inactive_timer) == 1) - put_task_struct(dl_task_of(dl_se)); + put_task_struct_atomic_safe(dl_task_of(dl_se)); } else { /* * Since "dl_non_contending" is not set, the @@ -1207,7 +1207,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) * This can free the task_struct, including this hrtimer, do not touch * anything related to that after this. */ - put_task_struct(p); + put_task_struct_atomic_safe(p); return HRTIMER_NORESTART; } @@ -1442,7 +1442,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) dl_se->dl_non_contending = 0; unlock: task_rq_unlock(rq, p, &rf); - put_task_struct(p); + put_task_struct_atomic_safe(p); return HRTIMER_NORESTART; } @@ -1899,7 +1899,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused * so we are still safe. */ if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + put_task_struct_atomic_safe(p); } sub_rq_bw(&p->dl, &rq->dl); rq_unlock(rq, &rf); @@ -2351,7 +2351,7 @@ static int push_dl_task(struct rq *rq) /* No more tasks */ goto out; - put_task_struct(next_task); + put_task_struct_atomic_safe(next_task); next_task = task; goto retry; } @@ -2366,7 +2366,7 @@ static int push_dl_task(struct rq *rq) double_unlock_balance(rq, later_rq); out: - put_task_struct(next_task); + put_task_struct_atomic_safe(next_task); return ret; } @@ -2633,7 +2633,7 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) static void switched_to_dl(struct rq *rq, struct task_struct *p) { if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + put_task_struct_atomic_safe(p); /* If p is not queued we will update its parameters at next wakeup. */ if (!task_on_rq_queued(p)) { diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 0a11f44adee5..e58a84535f61 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2150,7 +2150,7 @@ static int push_rt_task(struct rq *rq, bool pull) /* * Something has shifted, try again. */ - put_task_struct(next_task); + put_task_struct_atomic_safe(next_task); next_task = task; goto retry; } @@ -2163,7 +2163,7 @@ static int push_rt_task(struct rq *rq, bool pull) double_unlock_balance(rq, lowest_rq); out: - put_task_struct(next_task); + put_task_struct_atomic_safe(next_task); return ret; }