From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.178 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794315115; b=kvUeXpzXD1SJpx1xsGKxmU6YTx+5YVSrwxSCS0kOmBRoCzqb7ROFL7E2tenhsQwuu8sW c1/T2VQdGmK/WoyeALAxAMLJSBH82/+FvUoj5Wjwtriv3/Lyr7RvBnG1uhvRMbWDE7z+1 f5cgST9xxl5+BvoimObr7+yauxxE7lIV/8qy39LcG+tsCgbcRlku78KCa+Vbhkf4bDFKX bl6ytPXNQx9jFlYVsxOQMU1VFs2I1YRtbZ9T+piVttNk5GNIYVI5Y+wkWopyps7g5rCte GTOtUlNyeAxqv2w16azzuSlelSpoyftnUVE/aHzNbtaT4+d1YiWTc1Bg6r44faUgLPw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794315115; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=NTyrgE/NhXynhM9E29qnV24j4tJQyNRVjWGGUarqaBw=; b=JHV2lj+wkMvQO91HVSf2FYgQ7mWSLyqaaVczJRaeH5JtdxC3TSA+GXuCVFAncLuGSstD vaWiARKfWOhiujjVnJspYSYAHcnA7x6bDWnT+XGCA10x1Sx0oI2AYn19zCygaIgvUALGU UllhfqN0iz2E9D2/Qh8vdhNLXs7QR5eYVYc64ieSbe/hw0+MuJC+6333bATUD4XK2QPO2 obbg9cr7mHL/lSvlv12zEA11KwKS4qgX4jzeHGKSXqfAvtmhMKFaiMxA94LdvFZYHECQT hKPslqC9zB7+pqUTTjT7srv0qQR+048UzBNtMrY9ulCx1g2jC4GPqf3SjAKVrO/hmvA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=hFpWf8yL; arc=none smtp.remote-ip=91.218.175.178 Received: from mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A938660A2617 for ; Tue, 10 Nov 2026 12:51:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A938660A2617 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=hFpWf8yL X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=RSQqPLCzjXzhj+yupFqjdMSCPLeZDniTWxY3yX5md4k=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794315112; v=1; x=1794919912; b=hFpWf8yL6oDW6NM8mtVSFMeRx7ackcDZIx2TXPgmfnP7JapwXw8H7ZJnu7sdJ3iMvZ9hGaAa 7wkZMbsiH22HGm+8PcCw/yrkJWPxXtl1gI1mQ/FkTmK2abJ4JhAZW49r5eflssC9OL2SxaKYaIs 1P5UA4418lmP3F0DfPoqZPLI= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 47c838edafd7a544; Tue, 10 Nov 2026 12:51:52 +0000 X-Mizu-Trace-ID: 47c838edafd7a544 X-Migadu-Flow: FLOW_OUT From: Tao Cui To: tj@kernel.org Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, liwanwu@kylinos.cn, devnexen@gmail.com, zhaomengmeng@kylinos.cn, emil@etsalapatis.com, yphbchou0911@gmail.com, mingo@redhat.com, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, cui.tao@linux.dev, Tao Cui Subject: [PATCH 9/9] tools/sched_ext: scx_userland: Reject batch size 0 Date: Tue, 10 Nov 2026 20:50:01 +0800 Message-ID: <20261110125001.4167503-10-cui.tao@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110125001.4167503-1-cui.tao@linux.dev> References: <20261110125001.4167503-1-cui.tao@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tao Cui -b 0 is accepted silently and leaves batch_size at zero, so dispatch_batch() never moves a task out of the vruntime list into the dispatched queue: tasks pile up on the vruntime list while nr_scheduled stays positive and ops.update_idle() keeps kicking cpus; the system-wide livelock ends when the stall watchdog kills the scheduler. Reject a zero batch size at option parsing. Fixes: cc4448d0856d ("tools/sched_ext: add scx_userland scheduler") Signed-off-by: Tao Cui --- tools/sched_ext/scx_userland.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/sched_ext/scx_userland.c b/tools/sched_ext/scx_userland.c index b16b6db5f365..cbd511685449 100644 --- a/tools/sched_ext/scx_userland.c +++ b/tools/sched_ext/scx_userland.c @@ -364,6 +364,11 @@ static void pre_bootstrap(int argc, char **argv) } } + if (!batch_size) { + fprintf(stderr, "Invalid batch size %s\n", optarg); + exit(1); + } + /* * It's not always safe to allocate in a user space scheduler, as an * enqueued task could hold a lock that we require in order to be able -- 2.53.0 base-commit: 5b740a72b55c4267ba4d8010f17dde26b26f52d3