From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 463E8314B95 for ; Thu, 11 Jun 2026 02:14:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781144096; cv=none; b=vAdwRJEb+Q4Ars9uU+FakU380h/nf/p6NCeF5mONl/5Ar6lHl+JKrMpS99ZzBhdw+c6frGgRB6pUaBIwQy1/rjcZ+JaX5+TQ847jInMDcyiI1kA1CtGi9e5MU0YxOf/0/ovbb7TXAVmavLCr7+7BaZxzjniLwboAWZuJhZ/1i8I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781144096; c=relaxed/simple; bh=9zmHfkdlF96eCifUKooKR00F8Xhw8irUJG3x0Y9YJP0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PpeYh/+sTiM7ZiRfTdg2pe7p5+JFdRaDBjDDF7ki5kTtaSty7FV2/VkU9MUYs+oeD8kmfTsxZabf90YTBqkehHUyA1xcXaki7QQAPB3NR9qtjll4bVV0+hFy8UjLX8vi59TPBIvQqV7HXdY/ak+g8XaFc+AM987/G5F4ESpisU8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=surriel.com; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b=CHzrv/GV; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=surriel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b="CHzrv/GV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=6Sgep7daiknmKVaAgSjJE37QUaA33s6HPcj3C0VdhbU=; b=CHzrv/GVvE946h1ozdu5QD5ow7 ICYGLQcXdyCRqu/ifkKu/9n4q/M3syQO2QFRMeOWtdKZ4stGSp4X9q0+Eeaegz7wgupVcUDWKiBa2 iAE1SUpHsIoQ15wGEXQ1sXG1KpFKJUrNJo2sZCDrkOGYT7TP/L989B8Gbrmq7RhbkS3+0gbLyTkX8 4/6GN0p6J4rg0D7g8JnJbq/+6vTCdaoRzkmu67TgOaX01+8ASW7sXD1vjWUqHIT8DKqc0gMztJeBl SO69Y8bQxu9TjnvJ2Rjup9P6BqwzZgymtetyxWEkOr5xKM7Z3C/J0h3t6CT4jKnToJpVRj2ZcM0yf Ntv+LRfQ==; Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1wXUwJ-000000003Zo-0pj3; Wed, 10 Jun 2026 22:14:39 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, vschneid@redhat.com, Rik van Riel Subject: [PATCH 8/9] sched/deadline: defer WARN console output under rq->lock Date: Wed, 10 Jun 2026 22:14:15 -0400 Message-ID: <20260611021416.910555-9-riel@surriel.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260611021416.910555-1-riel@surriel.com> References: <20260611021416.910555-1-riel@surriel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Convert the WARN*() calls that run under rq->lock or ->pi_lock to the SCHED_WARN*() variants, so their console output is deferred to irq_work instead of being emitted synchronously (which can deadlock via console_unlock() -> up(&console_sem) -> try_to_wake_up() while the lock is held). This should prevent a deadlock if these warnings fire with a legacy or boot console configured. Signed-off-by: Rik van Riel Assisted-by: Claude:claude-opus-4-8 --- kernel/sched/cpudeadline.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index 0a2b7e30fd10..271f28b87a4e 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -149,7 +149,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, } else { int best_cpu = cpudl_maximum(cp); - WARN_ON(best_cpu != -1 && !cpu_present(best_cpu)); + SCHED_WARN_ON(best_cpu != -1 && !cpu_present(best_cpu)); if (cpumask_test_cpu(best_cpu, &p->cpus_mask) && dl_time_before(dl_se->deadline, cp->elements[0].dl)) { @@ -177,7 +177,7 @@ void cpudl_clear(struct cpudl *cp, int cpu, bool online) int old_idx, new_cpu; unsigned long flags; - WARN_ON(!cpu_present(cpu)); + SCHED_WARN_ON(!cpu_present(cpu)); raw_spin_lock_irqsave(&cp->lock, flags); @@ -220,7 +220,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl) int old_idx; unsigned long flags; - WARN_ON(!cpu_present(cpu)); + SCHED_WARN_ON(!cpu_present(cpu)); raw_spin_lock_irqsave(&cp->lock, flags); -- 2.53.0-Meta