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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7510C433DF for ; Mon, 3 Aug 2020 13:24:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E68F20738 for ; Mon, 3 Aug 2020 13:24:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596461083; bh=2P+e2agXRGcCDzDHK4A1fBjviZ3qjpqZf+OAaU5r/yI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=cuKFpZFRmB7IO9zjKa8SpNPIIBVvLLbvy8fNT6W254wYRsE7XbO2zpbnrTYDS6lZC 97MhKRALXrhRwsRBKdEaNizqwn38Xc47QKQZk2yadvvA90mx4WgoV7ogNXEWZV3VKa X3Y0+a8XYrsl/BpGNoj8f687T1rFzDsEI4zUGjmo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726981AbgHCNYn (ORCPT ); Mon, 3 Aug 2020 09:24:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:47358 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726509AbgHCNYm (ORCPT ); Mon, 3 Aug 2020 09:24:42 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E92F8206DA; Mon, 3 Aug 2020 13:24:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596461081; bh=2P+e2agXRGcCDzDHK4A1fBjviZ3qjpqZf+OAaU5r/yI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=c9a7+KENOfxIs/9Iy0vX6YmkAbT9I0gWZfOk+2qE3wyDmUQ8+1XKIonsF9mYrgMoo NXZ6S1ltT2KaaZZopvvYsND60TMzjzkYAO62THhGEenXbB1aSZ/DlkQodEId8wu7J8 QBUWGbpWbwl8wBmW5XfkMD3LuAuIHGcqpf12w/68= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1k2aSF-00H7Mr-Vt; Mon, 03 Aug 2020 14:24:40 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 03 Aug 2020 14:24:39 +0100 From: Marc Zyngier To: Valentin Schneider , Vladimir Oltean Cc: Robin Murphy , Kurt Kanzenbach , paulmck@kernel.org, Anna-Maria Gleixner , catalin.marinas@arm.com, Alison Wang , linux-kernel@vger.kernel.org, leoyang.li@nxp.com, vladimir.oltean@nxp.com, Thomas Gleixner , mw@semihalf.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting In-Reply-To: References: <20200729033934.22349-1-alison.wang@nxp.com> <877dumbtoi.fsf@kurt> <20200729094943.lsmhsqlnl7rlnl6f@skbuf> <87mu3ho48v.fsf@kurt> <20200730082228.r24zgdeiofvwxijm@skbuf> <873654m9zi.fsf@kurt> <20200803081625.czdfwcpw5emcd4ls@skbuf> <20200803113841.pqqpo4hqfwru3upq@skbuf> User-Agent: Roundcube Webmail/1.4.5 Message-ID: <34b6cca5355f9e709554892261ac4b0c@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: valentin.schneider@arm.com, olteanv@gmail.com, robin.murphy@arm.com, kurt.kanzenbach@linutronix.de, paulmck@kernel.org, anna-maria@linutronix.de, catalin.marinas@arm.com, alison.wang@nxp.com, linux-kernel@vger.kernel.org, leoyang.li@nxp.com, vladimir.oltean@nxp.com, tglx@linutronix.de, mw@semihalf.com, will@kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-08-03 12:48, Valentin Schneider wrote: > On 03/08/20 12:38, Vladimir Oltean wrote: >> On Mon, Aug 03, 2020 at 10:51:32AM +0100, Robin Murphy wrote: >>> >>> Having glanced across another thread that mentions IRQ accounting >>> recently[1], I wonder if the underlying bug here might have something >>> do to >>> with the stuff that Marc's trying to clean up. >>> >>> Robin. >>> >>> [1] >>> https://lore.kernel.org/linux-arm-kernel/20200624195811.435857-16-maz@kernel.org/ >> >> Thanks Robin. I've applied Marc's "[PATCH v2 00/17] arm/arm64: Turning >> IPIs into normal interrupts" series and the LS1028A I'm debugging >> hangs >> in absolutely the same way. >> > > I'm not too surprised by that, wrt accounting this mostly changes where > the > stores go to and barely shuffles when they happen (slightly earlier on > the > IPI handling path). Indeed. This series is just a "let's make things be the way they should be", and isn't really fixing any bug. It actually may introduce a couple... > FWIW I've had 'stress-ng --hrtimers 1' running on my Juno and eMAG for > ~15 > minutes and haven't had a splat yet. I've started a couple of VMs with that workload too. 400K irq/s on an 8 vcpu guest, nothing to report so far. But removing IRQ_TIME_ACCOUNTING from defconfig is a resounding "no way!". It looks like we have a bug, and it should be squashed, not glanced over. M. -- Jazz is not dead. It just smells funny... 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Mon, 03 Aug 2020 14:24:40 +0100 MIME-Version: 1.0 Date: Mon, 03 Aug 2020 14:24:39 +0100 From: Marc Zyngier To: Valentin Schneider , Vladimir Oltean Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting In-Reply-To: References: <20200729033934.22349-1-alison.wang@nxp.com> <877dumbtoi.fsf@kurt> <20200729094943.lsmhsqlnl7rlnl6f@skbuf> <87mu3ho48v.fsf@kurt> <20200730082228.r24zgdeiofvwxijm@skbuf> <873654m9zi.fsf@kurt> <20200803081625.czdfwcpw5emcd4ls@skbuf> <20200803113841.pqqpo4hqfwru3upq@skbuf> User-Agent: Roundcube Webmail/1.4.5 Message-ID: <34b6cca5355f9e709554892261ac4b0c@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: valentin.schneider@arm.com, olteanv@gmail.com, robin.murphy@arm.com, kurt.kanzenbach@linutronix.de, paulmck@kernel.org, anna-maria@linutronix.de, catalin.marinas@arm.com, alison.wang@nxp.com, linux-kernel@vger.kernel.org, leoyang.li@nxp.com, vladimir.oltean@nxp.com, tglx@linutronix.de, mw@semihalf.com, will@kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200803_092443_311696_EB09AA59 X-CRM114-Status: GOOD ( 17.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: paulmck@kernel.org, Robin Murphy , Alison Wang , linux-kernel@vger.kernel.org, leoyang.li@nxp.com, vladimir.oltean@nxp.com, will@kernel.org, catalin.marinas@arm.com, Kurt Kanzenbach , Thomas Gleixner , mw@semihalf.com, Anna-Maria Gleixner , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-08-03 12:48, Valentin Schneider wrote: > On 03/08/20 12:38, Vladimir Oltean wrote: >> On Mon, Aug 03, 2020 at 10:51:32AM +0100, Robin Murphy wrote: >>> >>> Having glanced across another thread that mentions IRQ accounting >>> recently[1], I wonder if the underlying bug here might have something >>> do to >>> with the stuff that Marc's trying to clean up. >>> >>> Robin. >>> >>> [1] >>> https://lore.kernel.org/linux-arm-kernel/20200624195811.435857-16-maz@kernel.org/ >> >> Thanks Robin. I've applied Marc's "[PATCH v2 00/17] arm/arm64: Turning >> IPIs into normal interrupts" series and the LS1028A I'm debugging >> hangs >> in absolutely the same way. >> > > I'm not too surprised by that, wrt accounting this mostly changes where > the > stores go to and barely shuffles when they happen (slightly earlier on > the > IPI handling path). Indeed. This series is just a "let's make things be the way they should be", and isn't really fixing any bug. It actually may introduce a couple... > FWIW I've had 'stress-ng --hrtimers 1' running on my Juno and eMAG for > ~15 > minutes and haven't had a splat yet. I've started a couple of VMs with that workload too. 400K irq/s on an 8 vcpu guest, nothing to report so far. But removing IRQ_TIME_ACCOUNTING from defconfig is a resounding "no way!". It looks like we have a bug, and it should be squashed, not glanced over. M. -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel