From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 BC3051BB686 for ; Thu, 1 Aug 2024 16:36:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722530181; cv=none; b=kIzBCADjMXiJp11vQMUmxKXFmsnvuhh3ZB5hWGN0qh8GljWMgPubo5Zscev9WECL6unrc4wtGmVAbTLDpmn/mGjNyCNFR5klYiK8HYexXq59y4Fnjsr7y3MOaftm+mdihGwpOhzizDv0l67XRN+1GGmKp6WBXCqijzYhJSMPO3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722530181; c=relaxed/simple; bh=6MYtvNwqzr89kuMijj7dj05YG0cddZdYGXuIn2AaA/k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RnqeF0fSD9Iao4Jyea3GrihQb0vH6O5ou+dGl/SuSYhJZ3qYaEM9/lOzZPrSq3DDoTKa6hNXSg7rPAU5vjBAfyim8Rzte+bRPVYmeIBCw+xjh0vTicrmNvHMojxhn+JMQ81SMC19gO8lQTHgmseJCSO+RL6URNvlwcJony2QijY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=cddZt4X2; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="cddZt4X2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=SaIPytHxWcAaYza32KmNAPXihLWLj5CDb3e50E+sMRQ=; b=cddZt4X2EOKhHMr2SS7Oecnifx oGjj4+9YuXZMQi4YdWfEX0j4UPccH3G9E5JzTCDEBoMRBFwNoSsQ302iKdPkZJRknC9vcMxcyXkG4 QYfxVOJZbFZfqbAm5/lxLGoawvXH8rJbDYQ8W0WXd91IMuof5olo9xZwkLdlK+WNEpdfmpT8GaRDM n9wMctRP9JawI+VOOb5vqOLhdnyBEe1BR4FMYQbFU0ZfRSy32Zlwb6sGVIzKX3o8/XhfqyxMaIFgD a1PU3J7EB1zt8RVNoF6QSILWEGqkg9gGwNXEx5dwoNFQi6Vfcprmm4gqPLJKcAplRdxGLGhnDbOys Sm1GZFMQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:36698) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sZYmV-0003Wu-3C; Thu, 01 Aug 2024 17:36:00 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sZYmY-0007EW-5x; Thu, 01 Aug 2024 17:36:02 +0100 Date: Thu, 1 Aug 2024 17:36:02 +0100 From: "Russell King (Oracle)" To: Jinjie Ruan Cc: dianders@chromium.org, mhocko@suse.com, akpm@linux-foundation.org, maz@kernel.org, vschneid@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: smp: Fix missing backtrace IPI statics Message-ID: References: <20240801094022.1402616-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240801094022.1402616-1-ruanjinjie@huawei.com> Sender: Russell King (Oracle) On Thu, Aug 01, 2024 at 05:40:22PM +0800, Jinjie Ruan wrote: > It is similar to ARM64 commit 916b93f4e865 ("arm64: smp: Fix missing IPI > statistics"), commit 56afcd3dbd19 ("ARM: Allow IPIs to be handled as normal > interrupts") set CPU_BACKTRACE IPI "IRQ_HIDDEN" flag but not show it in > show_ipi_list(), which cause the interrupt kstat_irqs accounting > is missing in display. I don't see why this needs to be included. If this IPI fires, it means that the kernel has suffered a lockup and is probably not very useful. So the chances of being able to read out from /proc/interrupts a non- zero "CPU backtrace interrupts" figure is highly unlikely. So, I don't see much point to this change. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!