From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (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 0AE6E36CE1B; Wed, 8 Apr 2026 03:11:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775617899; cv=none; b=dV9AOnH35UY6XC1Uuq3M1d12zbbrsuYRFu7ScraNKFnVCDlpIW/IEHYNgPeExJSrXdzC8UYOJA2Y7W6QNqTJTtoiB2v0nXxbtS1bqMW8snfNHyw4VJhyCVQ/V8LQwtIFw8gHSgCL12bzdTpQgTmjUlNPQdtmYS1wjuBuGi2ZiaE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775617899; c=relaxed/simple; bh=B1tWgEjuz3KZXwwLjxHy5eXx1NPU3fgj7Awk5SfugHE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nXZqoTAPoBOWJA8vdIQQ4MV/vX2quIkNt3sDxeHTjZ8/DUGHRoR/YeaWpPXE/35B1F8Y3Y4FL2epgSyzbeBRxP4BH/L1uKEABhuuy4EqdZps/hLzSFBA5IE+HT1ODZYm8SpvuNJB4dGzOMs+8q4V18NNjpEy7sG6/Eo+cEO9Rfg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=WjoqAnUA; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="WjoqAnUA" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version: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: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=4ufVw0Zm3U/wyVJGFUBwpGBW6jX4QZy5m/HG0FHs7aU=; b=WjoqAnUAJGQ1nCC9WcMCZc4cd+ Y8bNt8s99UsLHmumbKdYsktk9iCZvJt2dWZQA89bTQ0yuNclH2XBaBcha4eFAbXlz6e4RzY9a0Gvu fkmNsY2cO/OFbATh49U+1zo1PXGHGiLYsLElSLrCxmB0Azmjhyknzfdl6C3yFKT8Hndz/s17mf8Mc amU5dmfYg+7vhQ/yGDthSs54TS9tW/QWCxykO1siSefXeUTmvTanRFaceqaXwJJENcHWnyomMF9VR OelLITW+Ecpym/XKeqDjanDqR050dNffMA8hsG6GTPTANzaRqqr7IPBkKiasaw93TFIlgs+xu45re 9QfY4VCA==; Received: from [58.29.145.179] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wAJK6-00DIXo-IA; Wed, 08 Apr 2026 05:11:23 +0200 From: Changwoo Min To: tj@kernel.org, void@manifault.com, arighi@nvidia.com, changwoo@igalia.com Cc: kernel-dev@igalia.com, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] sched_ext: Improve watchdog stall diagnostics Date: Wed, 8 Apr 2026 12:11:11 +0900 Message-ID: <20260408031113.76005-1-changwoo@igalia.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When a watchdog timeout fires on a system with many CPUs, the per-CPU state dump in the exit info can get truncated. If the stall CPU happens to be in the middle or end of the CPU list, its state may never appear in the output, making it difficult to diagnose the hang. This series addresses that by always dumping the stall CPU first. Patch 1 is a preparatory refactor that extracts the per-CPU dump logic into a scx_dump_cpu() helper, making patch 2 straightforward. Patch 2 adds a stall_cpu field to scx_exit_info, threads it through the exit path, and reorders the dump loop to emit the stall CPU before all others. Changwoo Min (2): sched_ext: Extract scx_dump_cpu() from scx_dump_state() sched_ext: Dump the stall CPU first in watchdog exit kernel/sched/ext.c | 202 +++++++++++++++++++----------------- kernel/sched/ext_internal.h | 3 + 2 files changed, 112 insertions(+), 93 deletions(-) -- 2.53.0