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 BE27DC001B3 for ; Mon, 3 Jul 2023 18:33:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229943AbjGCSdp (ORCPT ); Mon, 3 Jul 2023 14:33:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229978AbjGCSdn (ORCPT ); Mon, 3 Jul 2023 14:33:43 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CD7810CA for ; Mon, 3 Jul 2023 11:33:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1AB376100C for ; Mon, 3 Jul 2023 18:33:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 731C0C433C7; Mon, 3 Jul 2023 18:33:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688409204; bh=pVRd8azkONAtwKeXjXh6CxQ/T2nHYxJNl4eiPrSZYTk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=huMQTbmGJqCkpY5Bk+88WjXGBuBYulSolvITtJWZmFiDb+3opC3GBWrxhILDcoh/F b/uxKAAUD7buDYBDVB0v0ledYe4kByft5rlCMpiLgPMsNOdBOz/QGFDAY55Xt+vWLM hNDwuSzmBENlcRdjW19AslsRtQvvZ5bNVng6zzaVDQ17+/5oyq7/FnCPT8obKDAn45 eb6CNzHuvFeZbSpvQ2X/aIK4teZ424yp3xjxOTNjQR9iaYmT87xSBAxvqVBtA9as57 ZPmAgB4+Js5Xt4lp6IRWZzn+/k1BGdQJvHdmHV7me14hZFI4DA4VIZ7IzhOjtjLAxJ 0WtKkdLAE3mfg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qGOMU-00AErW-5d; Mon, 03 Jul 2023 19:33:22 +0100 Date: Mon, 03 Jul 2023 19:33:21 +0100 Message-ID: <86zg4cx2tq.wl-maz@kernel.org> From: Marc Zyngier To: Palmer Dabbelt Cc: Linus Torvalds , Conor Dooley , apatel@ventanamicro.com, oliver.sang@intel.com, Liam.Howlett@oracle.com, linux-kernel@vger.kernel.org, lkp@lists.01.org, lkp@intel.com Subject: Re: [mm] 408579cd62: WARNING:suspicious_RCU_usage In-Reply-To: References: User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: palmer@rivosinc.com, torvalds@linux-foundation.org, conor@kernel.org, apatel@ventanamicro.com, oliver.sang@intel.com, Liam.Howlett@oracle.com, linux-kernel@vger.kernel.org, lkp@lists.01.org, lkp@intel.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 03 Jul 2023 19:11:27 +0100, Palmer Dabbelt wrote: > > On Mon, 03 Jul 2023 10:46:55 PDT (-0700), Linus Torvalds wrote: > > On Mon, 3 Jul 2023 at 10:34, Marc Zyngier wrote: > >> > >> Comparing with what we do on arm64, a less radical change would be to > >> move the IPI init after notify_cpu_starting(), which explicitly > >> enables RCU usage. > > > > Ack, that looks right to me. > > I don't see anything wrong with it and it's passing my tests, but > we've got a handful of ways to boot so it's all a bit messy and I > might be messing something. > > I'm still catching up a bit as I took both days off this weekend. > Hopefully just an oversight in a bigger rafactoring, but I'll give it > another look. > > Marc: are you going to send that as a patch? Just did [1]. Thanks, M. [1] https://lore.kernel.org/r/20230703183126.1567625-1-maz@kernel.org -- Without deviation from the norm, progress is not possible.