From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout5-smtp.messagingengine.com (fout5-smtp.messagingengine.com [103.168.172.148]) (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 98901219FC for ; Fri, 8 Mar 2024 09:14:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.148 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709889253; cv=none; b=kQo7RhRjXMNagC1z6d4a2KhY8XHhnyiwrqIYtT2c5JJ373RV/9raBbkg0O+UShFziLa+lR6IorNKQjjQKJMN21OoRNmjkdIScz6TB0FprDGbqCj3502Hw6STSWvZaV8DWnqQ3evuX74kWoW8JRPas29md6qvkgvoUE07OC7hZoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709889253; c=relaxed/simple; bh=H+WALQkyfo1vnes2a3seC9FEQ8x5gZJKNfldFBzNuKk=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=ZIo/QcBBOpcwsbEajC60jRWI07NyPoVHES2NBwFpRaijj+eCoz/la+JBggg3bPqESlB5j/dp+VB4NTESIA4R4AL3rJz3VqkpGXreS+CrBpANc1tT4vNSXcXOWBadIAn81oHCST7nLpV0qQp5EUm8IWQCxF35g8yqmTJtWTYw1NU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org; spf=none smtp.mailfrom=linux-m68k.org; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=hxVoe7Jz; arc=none smtp.client-ip=103.168.172.148 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux-m68k.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="hxVoe7Jz" Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailfout.nyi.internal (Postfix) with ESMTP id 4D0E913800EF; Fri, 8 Mar 2024 04:14:09 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Fri, 08 Mar 2024 04:14:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1709889249; x=1709975649; bh=OJgCp9qq0kifVkVkqrGSeucHlNMK PIVBmrQ+wnT6lwo=; b=hxVoe7JzWqU0lINoyZnOfe86YnHkL0HNnxyf6PSVOtOT PBSAIfg1r498MFUmCI+DhUsb9aNzuApMcTH/Och1phD4inUOocAvdHP5Vi7EbWg9 FWD8p0TvspnbmFCzWyRT7sm3ugtwihf9C9V1oK+uEg2BqkWhPFU06d72aU+XIZeP QdI5uL9sQIqIkEcbLmrzN8c68K5/2pgbw37Dd19h2tu/e11BEmk3+CehqwE7cSAB j4l5nd4/wouQO1JHQ+BpNkMxPLARU8EWRZqSmKLVQ4x9gTECLEm0fj8yEe2tQMc2 0oLaN3Js+whzIeACEGzwY6h4SjwzBAxivcHSP4b4Ww== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrieehgddtudcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvvefujgfkfhggtgesthdtredttddtvdenucfhrhhomhephfhinhhnucfv hhgrihhnuceofhhthhgrihhnsehlihhnuhigqdhmieekkhdrohhrgheqnecuggftrfgrth htvghrnhepleeuheelheekgfeuvedtveetjeekhfffkeeffffftdfgjeevkeegfedvueeh ueelnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepfh hthhgrihhnsehlihhnuhigqdhmieekkhdrohhrgh X-ME-Proxy: Feedback-ID: i58a146ae:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 8 Mar 2024 04:14:06 -0500 (EST) Date: Fri, 8 Mar 2024 20:15:11 +1100 (AEDT) From: Finn Thain To: Michael Schmitz cc: Guenter Roeck , Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org Subject: Re: spinlock recursion when running q800 emulation in qemu In-Reply-To: <6eeccba7-6877-dd3c-2a67-94ea448bead6@gmail.com> Message-ID: References: <07811b26-677c-4d05-aeb4-996cd880b789@roeck-us.net> <0ccf5e42-63ec-a63d-9ee9-7043947637c3@gmail.com> <40205038-a7cd-2568-5f8e-2540aca2f84d@linux-m68k.org> <56f79fc8-1a62-48af-b2fb-cddace7c828f@gmail.com> <60029130-022e-8ec7-2dc5-678b077f1d69@linux-m68k.org> <6eeccba7-6877-dd3c-2a67-94ea448bead6@gmail.com> Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Fri, 8 Mar 2024, Michael Schmitz wrote: > > > IMHO, Gueunter would do better to instrument the spinlock tests on the > > assumption that the locking in arch/m68k really is correct. > > I've come to agree - maybe logging any run queue locks taken by the init > task with IRQs enabled might help? > If I understood how the spinlock test algorithm worked, I'd be adding sanity checks to it to test the assumptions underlying that algorithm. I would not be surprised if it uses logic that sees irqs_disabled() and then assumes that all hard irqs are disabled, or something similar. I don't think I'd be adding printk() because the BUG is intermittent and printk() messes with timing.