From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7C2F8C47073 for ; Tue, 9 Jan 2024 12:34:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A880B10E428; Tue, 9 Jan 2024 12:34:39 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) by gabe.freedesktop.org (Postfix) with ESMTPS id BAB1510E428 for ; Tue, 9 Jan 2024 12:34:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1704803678; x=1736339678; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=0+i9jNaZkLVNkMhEy1xoIRC1vMa04epFDEIpHpKX834=; b=dt/0d7kOENasR0IPGhNpLKMitI5U6Zn6qHD+bLaMk0qg960etGNcMfYs VjzIPA1m6wTOOnM/x0V8+DZbiuMaKG1DjJhV8/yQhnLDPBXh7BfVs3cQn AP/3xV6VGL6YG1EQceOp+thTfcZEYsokFqj9F6QYyi4VpMc7KLg9zWa4g SbZkg381FvFo2I/X4hf6Px0ZEPMDpBWr5GBtHEURIHQ9qaCJfHNMYqspp CbNAXEoKAJt+o8uxWYPEX5r51H93WBvCpfG1BZ+CAcXKyPQDoxpDrXHVq eQy3hQpHxviz65Kab4VFKMN74QEBZzvG9z7lpWUJHTfSnMEqUcs01G2jN A==; X-IronPort-AV: E=McAfee;i="6600,9927,10947"; a="11669982" X-IronPort-AV: E=Sophos;i="6.04,182,1695711600"; d="scan'208";a="11669982" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2024 04:34:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10947"; a="955003874" X-IronPort-AV: E=Sophos;i="6.04,182,1695711600"; d="scan'208";a="955003874" Received: from jlawryno-mobl.ger.corp.intel.com (HELO [10.217.160.86]) ([10.217.160.86]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2024 04:34:36 -0800 Message-ID: <3f972271-cf39-49f7-8f2c-568a78cd57c6@linux.intel.com> Date: Tue, 9 Jan 2024 13:34:34 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 05/10] accel/ivpu: Fix potential infinite loops in IRQ handlers To: Jeffrey Hugo , dri-devel@lists.freedesktop.org References: <20240105112218.351265-1-jacek.lawrynowicz@linux.intel.com> <20240105112218.351265-6-jacek.lawrynowicz@linux.intel.com> <663dc292-0aa0-367c-e2f3-ade7ffba3b94@quicinc.com> Content-Language: en-US From: Jacek Lawrynowicz Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <663dc292-0aa0-367c-e2f3-ade7ffba3b94@quicinc.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 05.01.2024 17:35, Jeffrey Hugo wrote: > On 1/5/2024 4:22 AM, Jacek Lawrynowicz wrote: >> Limit number of iterations in ivpu_mmu_irq_evtq_handler() and >> ivpu_ipc_irq_handler(). > > "potential infinite loops" sounds like something that has not been observed.  Has a problem actually occurred? > > Are you concerned that the FW is broken and spamming Linux with events? > > Why a limit of 100 events?  Seems arbitrary. > > I suspect threaded irqs might be useful here, but it is hard to tell. No, these problems were not observed yet. I think that the small size of the IPC/MMU queues and relatively fast host CPU prevent the host from being overloaded. Maybe let's drop this patch until there is a real issue then :)