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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4D5BC7619A for ; Sun, 2 Apr 2023 16:00:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230379AbjDBQAq (ORCPT ); Sun, 2 Apr 2023 12:00:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230330AbjDBQAo (ORCPT ); Sun, 2 Apr 2023 12:00:44 -0400 X-Greylist: delayed 383 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sun, 02 Apr 2023 09:00:42 PDT Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD50EC165 for ; Sun, 2 Apr 2023 09:00:42 -0700 (PDT) Received: from [10.36.2.154] (unknown [46.212.121.255]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 78113260C0B; Sun, 2 Apr 2023 17:54:18 +0200 (CEST) Message-ID: <7dc47823-01a1-ac19-73d4-4bf7eb07f98d@selasky.org> Date: Sun, 2 Apr 2023 17:54:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [Bug 217242] CPU hard lockup related to xhci/dma Content-Language: en-US To: bugzilla-daemon@kernel.org, linux-usb@vger.kernel.org References: From: Hans Petter Selasky In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 4/2/23 00:17, bugzilla-daemon@kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=217242 > > --- Comment #6 from Austin Domino (austin.domino@hotmail.com) --- > (In reply to Austin Domino from comment #4) >> The setup that created the output in the previous two attached log files is >> described in more detail in related posts on: >> >> Ubuntu Forums -> https://ubuntuforums.org/showthread.php … st14136903 >> and >> Ubuntu's Launchpad Bug Page -> https://bugs.launchpad.net/ubuntu/+sour … >> ug/2013390 > Try 3 (I wish I could edit posts, but I should not have pressed "Save Changes" > so quickly. Sorry about this comment and my incompetence): > > Here are the actual links: > > Ubuntu Forums -> > https://ubuntuforums.org/showthread.php?t=2485480&p=14136903#post14136903 > and > Ubuntu's Launchpad Bug Page -> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2013390 > Hi, I don't have access to the bugzilla, but this looks like a out of memory situation, and does not really point towards the USB XHCI. URB's are typically submitted using GFP_KERNEL, which allow memory allocators to sleep while waiting for more memory. GFP_ATOMIC does not allow sleeping. usb_submit_urb(xxx, GFP_KERNEL); While that being said, I wish the Linux USB core would take the example of the FreeBSD USB core, and pre-allocate all memory needed for USB transfers, also called URB's, during device attach. Frequently going through allocate and free cycles during operation, is not just inefficient, but also greatly degrades the ability to debug the system. USB is still quite essential when doing remote server access. Yeah, the serial port is great too, but one day inb() and outb() will die :-) --HPS