From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 48FBB111A8 for ; Wed, 9 Jul 2025 20:09:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752091769; cv=none; b=J+MFw5j3+fyAohTotv/nsT8tVViDemR2Z0GP9cDkzWx9BlBQNohdgj8RZ8ZmSFvFXCgZpeDl+WL/Hyzuq0otFsnLNAun2hj3AoR14L/iqLsZD00/3C57VtFY9iYMbST0GENkfSibHrnOr80K2yyYlNPLIbxwWnVf5YU9VWwasu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752091769; c=relaxed/simple; bh=ew437jZZzUtNEW+hKJWQw2cXISzgxG9iDRIQDnuG6dg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=W/54BMGv22qZpKbtwMfq++PDj7/u5mptr2SXv5lRNOKvvoqKZApQxCn9+bHPtbZWDf8fJv08K0p6WIxdiXoe7m+3pNrHy2shjY5lkhqU5LU07qFBL01X6wdb3JA7d+H3sui4dvl2JHzAhBqc7YNj77ZDROZlBi4p94ohKHcT1HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=cAOzdJxh; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="cAOzdJxh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1752091767; x=1783627767; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=ew437jZZzUtNEW+hKJWQw2cXISzgxG9iDRIQDnuG6dg=; b=cAOzdJxh0fNOu4+ui/iRw2sq3h6cRImgi4W7h8tX5UcfuTIjOtKd2x+7 CeRBceAA2/DVithOiHclLFztgGDX8QCRLk0kzt8D+eu4fk+24EOFoAMb1 +yT6R+avvrUwWu8dO1A4yZ6BmXeVXFOTMle1kv5QuH51eNg0ISFhrOovJ yvP7TYpaaYi/mH77ZmZXJ/a+tLdW44SPtbCSMbRD5qYm3hZCBUAbFCrDY E0JF2bofut2OyohNJPfmC4GRSGyVBLdPRBuPTsWj38qxThUdF6BCoHiP2 fLh/nvxJspNAgE82Rxs3ORF/RULK+vPezt8HwiYC8EPXkdOgGSeZ/J0Do A==; X-CSE-ConnectionGUID: vydI58Y1QhS/S3hRLaGhnA== X-CSE-MsgGUID: ctRMnf7hTnO/OjQEUez9WA== X-IronPort-AV: E=McAfee;i="6800,10657,11489"; a="56971988" X-IronPort-AV: E=Sophos;i="6.16,298,1744095600"; d="scan'208";a="56971988" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jul 2025 13:09:26 -0700 X-CSE-ConnectionGUID: pbREcFI9SoGVLEVrDuroiw== X-CSE-MsgGUID: Sm2uVTLkRtuv9BpAD9V/WA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,298,1744095600"; d="scan'208";a="161528138" Received: from lfiedoro-mobl.ger.corp.intel.com (HELO stinkbox) ([10.245.245.254]) by orviesa005.jf.intel.com with SMTP; 09 Jul 2025 13:09:24 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 09 Jul 2025 23:09:22 +0300 Date: Wed, 9 Jul 2025 23:09:22 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Sebastian Andrzej Siewior Cc: Ben Hutchings , linux-rt-users@vger.kernel.org, intel-gfx@lists.freedesktop.org, Debian kernel maintainers Subject: Re: PREEMPT_RT vs i915 Message-ID: References: <7c42fe5a6158445e150e7d63991767e44fc36d3d.camel@decadent.org.uk> <20250709194443.lkevdn6m@linutronix.de> Precedence: bulk X-Mailing-List: linux-rt-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250709194443.lkevdn6m@linutronix.de> X-Patchwork-Hint: comment On Wed, Jul 09, 2025 at 09:44:43PM +0200, Sebastian Andrzej Siewior wrote: > On 2025-07-09 20:30:26 [+0300], Ville Syrjälä wrote: > > > > > > It seems like the critical uncore lock is currently held in a lot of > > > places and potentially for a long time. > > > > It shouldn't be held for that long. I think it should just be > > a raw spinlock. > > What about I resubmit the series and we look again? I don't think the > lock should be made raw just to be done with it. Until someone actually does the work to confirm the thing is working reliably there's no point in posting anything. And IIRC the other remaining problem with RT was the spinlocks used inside tracepoints (which is uncore lock, and probably some vblank locks). So that too needs some kind of solution because it's going to very hard to debug the timing sensitive parts without the tracepoints. -- Ville Syrjälä Intel