From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=198.175.65.16 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793676859; b=a48NXWjkMSW4BMj+g6JSAZVoODTiD0H9wEUFuypAdku4Rcf5fYSwNi59wIj53Zk0yLyn tO1t3iQRxOwLvwDfjdmFd933tmr2cK338ZxQ8tYqdMboMbN18QSAXSbFVRPIf/rxI/7UD g7tpPYbztZarltyWUeBDBpClrHYTE7OLPPokmLtxyfgxtVfYd4hiwCpEsZiW2ukPDsi86 jxWIHh+smZ05jhSKx77d6d+RHiU89c9k3ta5XNLDM4wjjCvR74aM3hyKmMHYdfuIPnDtb M4KgBvyXQGljTbhbD0hp3sywM9SC955PIGnWP0WfTDzgI/rk+5EbSB7CAAGZ2b7AkLA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793676859; h=DMARC-Filter:DKIM-Signature:X-CSE-ConnectionGUID:X-CSE-MsgGUID: X-IronPort-AV:X-IronPort-AV:Received:X-CSE-ConnectionGUID: X-CSE-MsgGUID:X-ExtLoop1:X-IronPort-AV:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:MIME-Version:Content-Transfer-Encoding; bh=+KFQfvqCaAVoWksFQF0LdVmJUFSaH6S/BvTxXHwburA=; b=sJcPD54hf8GQJ9GaLjL+DWgAWKz41Lnhfh7ZdIeC00yYZaubpBcPmlPDjprbCuR4ZzvX 2nJVxK/0gWMf01r7KLNWEo2IxH8zKUbVMFkqcv1sio02De/ZMYTv7jkQm4WOuw1HVnRQT zH4FUA0JPQIRAvOpRLcup1eLEFfqTr2PJdcbo7+bYZ0EbPc6ueW3So2Dn91l0v/Ay4gln 5Ec9vEudFIfaZbvI36zFOj5nQkWH//Aw7ciTSAjZBPmcLQOJW0ngamXMJWhePRBoij1pg 0uNFkRS3NMobK5CLRyfDa7Q6EEaOtl/zfTdPYs2IQPKjCahNaZ6OZiLxBr/iZZ1yxLA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=CDlIj5cn; arc=none smtp.remote-ip=198.175.65.16 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF13A606A324 for ; Tue, 3 Nov 2026 03:34:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org CF13A606A324 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=CDlIj5cn DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1793676856; x=1825212856; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=542XoxkYrTGwr4XYb6PejvvnkDtwoRYMhJuHoaiJH28=; b=CDlIj5cnBNOdn3IBy3VW6VZd0liJWjANhfLK3XNgjaNEcFl9qjUNQtiW MrzqzVJ9SE7c7ezc6FHyKcUswecYCEvoaofilBsdtiSYXzOfb6mcQtDh0 boY9F7zUkGVtIJ3FYd2CNpK9LEROuDpi/ioKEv2GC9KZYFenFpZB/nfRU VhukHebGhcGJAEC7sTL5qb1bdsXrG73jk1ogB3ANKhEblHhC8yvlgtvqb 6awMGvAjF8QRylisADEM1ukjRDmBQfUCnDxDKxuVmfcG9bC0OmrKqBvcW X1cRZWl7/QuOt/olwSXgrYG7WTJO7zr+abQuW6x64owRTyGco6Mv9A0p6 A==; X-CSE-ConnectionGUID: eBu0daYQRfWM3IisrQ5XGw== X-CSE-MsgGUID: G5FVCCvdS2qOtqIJa6/8lw== X-IronPort-AV: E=McAfee;i="6800,10657,11954"; a="2380777" X-IronPort-AV: E=Sophos;i="6.27,192,1787036400"; d="scan'208";a="2380777" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2026 19:34:16 -0800 X-CSE-ConnectionGUID: NMDZ4cjjS1a3bf0mLYUIkA== X-CSE-MsgGUID: 5vNC+z7FT4KaU15RpzoLOg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,192,1787036400"; d="scan'208";a="6159817" Received: from junxiao.bj.intel.com ([10.238.152.95]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2026 19:34:12 -0800 From: Junxiao Chang To: jani.nikula@linux.intel.com, rodrigo.vivi@intel.com, matthew.brost@intel.com, thomas.hellstrom@linux.intel.com, airlied@gmail.com, simona@ffwll.ch, bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Cc: dev@lankhorst.se, junxiao.chang@intel.com Subject: [PATCH 0/2] drm/xe: drm/xe: Improve real-time performance by limiting stolen memory usage Date: Wed, 4 Nov 2026 11:27:30 +0800 Message-ID: <20261104032732.30681-1-junxiao.chang@intel.com> X-Mailer: git-send-email 2.43.0 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 Stolen memory access and allocation overhead can introduce latency spikes and jitter, which negatively impacts real-time performance on PREEMPT_RT kernels. To improve real-time determinism, this series minimizes stolen memory usage when running on an RT-enabled kernel: 1. It bypasses initial plane allocation from stolen memory to avoid hardware access latency, falling back to standard allocations. 2. It warns the user if the GSC microcontroller is active (which relies on stolen memory) and provides instructions on how to disable it. Junxiao Chang (2): drm/xe/display: Skip initial plane allocation from stolen memory on RT drm/xe/gsc: warn about GSC stolen memory usage on RT kernels drivers/gpu/drm/xe/display/xe_initial_plane.c | 6 ++++++ drivers/gpu/drm/xe/xe_gsc.c | 5 +++++ 2 files changed, 11 insertions(+) -- 2.43.0