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 lists.zx2c4.com (lists.zx2c4.com [165.227.139.114]) (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 A2D80C43334 for ; Thu, 7 Jul 2022 13:29:27 +0000 (UTC) Received: by lists.zx2c4.com (OpenSMTPD) with ESMTP id 05b6de00; Thu, 7 Jul 2022 13:29:25 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lists.zx2c4.com (OpenSMTPD) with ESMTPS id f2653bb7 (TLSv1.2:ECDHE-ECDSA-AES256-GCM-SHA384:256:NO) for ; Thu, 7 Jul 2022 13:29:23 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 34EB36203A; Thu, 7 Jul 2022 13:29:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91D64C3411E; Thu, 7 Jul 2022 13:29:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657200561; bh=RfVt62RPQam+7duiaNm7NJAvinYhlayfk2ThiTDJKAA=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=UgEqLqgE3QhLQjrwY65XSjtSHcK/yUdSkE48ywULCNnlr3Hgo7d9bfUROaIokGl1n /LI2+ysz3JomTHI+lU13uPJdUhWSAm5w0U76cpQfctP+vDBMGiyTij2OE75SjihzQd q10L9DHA4Br1TfMwerLaPVOGQ1KWulMLbpAW5IwvtzSVWncLJwKgQIPwyJTFB4ZSDV GHEf4XQ7H7Ae5gR9nsYLj1UEKguqFq5GfyTx6lbT+p3reACG0o3i2Ga8Wt/wtK/QtN pDuG5+5TLzWuUCOF87bmrT3cQkkIHgvl/m6VHyUmUNqDgNs+tSFAY2ucONn09fQV5N RoYrOP7yNDuwA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 301995C0458; Thu, 7 Jul 2022 06:29:21 -0700 (PDT) Date: Thu, 7 Jul 2022 06:29:21 -0700 From: "Paul E. McKenney" To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Uladzislau Rezki , "Alex Xu (Hello71)" , wireguard@lists.zx2c4.com, "Jason A. Donenfeld" , Joel Fernandes , Greg Kroah-Hartman , Xinhui.Pan@amd.com, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, Suren Baghdasaryan , rcu@vger.kernel.org, Hridya Valsaraju , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Theodore Ts'o , alexander.deucher@amd.com, Todd Kjos , uladzislau.rezki@sony.com, Martijn Coenen , Christian Brauner Subject: Re: CONFIG_ANDROID (was: rcu_sched detected expedited stalls in amdgpu after suspend) Message-ID: <20220707132921.GK1790663@paulmck-ThinkPad-P17-Gen-1> References: <1656421946.ic03168yc3.none@localhost> <20220628185437.GA1790663@paulmck-ThinkPad-P17-Gen-1> <1656443915.mdjoauhqe0.none@localhost> <79c6ad70-47d9-47fe-4bb4-33fcf356dd37@amd.com> <20220706175836.GI1790663@paulmck-ThinkPad-P17-Gen-1> <20220706204202.GJ1790663@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: paulmck@kernel.org Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" On Thu, Jul 07, 2022 at 09:30:39AM +0200, Christian König wrote: > Am 06.07.22 um 22:42 schrieb Paul E. McKenney: > > On Wed, Jul 06, 2022 at 08:09:49PM +0200, Uladzislau Rezki wrote: > > > On Wed, Jul 06, 2022 at 10:58:36AM -0700, Paul E. McKenney wrote: > > > > On Wed, Jul 06, 2022 at 07:48:20PM +0200, Uladzislau Rezki wrote: > > > > > Hello. > > > > > > > > > > On Mon, Jul 04, 2022 at 01:30:50PM +0200, Christian König wrote: > > > > > > Hi guys, > > > > > > > > > > > > Am 28.06.22 um 22:11 schrieb Uladzislau Rezki: > > > > > > > > Excerpts from Paul E. McKenney's message of June 28, 2022 2:54 pm: > > > > > > > > > All you need to do to get the previous behavior is to add something like > > > > > > > > > this to your defconfig file: > > > > > > > > > > > > > > > > > > CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=21000 > > > > > > > > > > > > > > > > > > Any reason why this will not work for you? > > > > > > sorry for jumping in so later, I was on vacation for a week. > > > > > > > > > > > > Well when any RCU period is longer than 20ms and amdgpu in the backtrace my > > > > > > educated guess is that we messed up some timeout waiting for the hw. > > > > > > > > > > > > We usually do wait a few us, but it can be that somebody is waiting for ms > > > > > > instead. > > > > > > > > > > > > So there are some todos here as far as I can see and It would be helpful to > > > > > > get a cleaner backtrace if possible. > > > > > > > > > > > Actually CONFIG_ANDROID looks like is going to be removed, so the CONFIG_RCU_EXP_CPU_STALL_TIMEOUT > > > > > will not have any dependencies on the CONFIG_ANDROID anymore: > > > > > > > > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org%2Flkml%2F2022%2F6%2F29%2F756&data=05%7C01%7Cchristian.koenig%40amd.com%7C8b36bcb4fe61475c0eb708da5f8ffce8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637927369274030797%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=eaK66spsbWVi2uRhcFK7eu4usgkHFZCSvErZxB%2F2npM%3D&reserved=0 > > > > But you can set the RCU_EXP_CPU_STALL_TIMEOUT Kconfig option, if you > > > > wish. Setting this option to 20 will get you the behavior previously > > > > obtained by setting the now-defunct ANDROID Kconfig option. > > > > > > > Right. Or over boot parameter. So for us it is not a big issue :) > > Specifically rcupdate.rcu_exp_cpu_stall_timeout, for those just now > > tuning in. ;-) > > I was just about to write a response asking for that :) > > Thanks, I will suggest to our QA to add this parameter while doing some > tests. Very good! Please let me know how it goes. Thanx, Paul