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 B98621E4A4 for ; Fri, 28 Jun 2024 13:14:06 +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=1719580448; cv=none; b=f23/69/gYcoMdClpdfl5spJw9Y45kDSjjTELWe+4Y9IPcDKj7GY2diak8Tr72NUPFdmU/vd1DEal8nIQeJrwgFA9xLKZ6V1KnFlNc8mmFQ6DRIqed8iIvfAqgBhMchkm6jtVI6dp39AfZkYMbW5XN6paL+eXkiaC8UfX+0MfHeM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719580448; c=relaxed/simple; bh=2yFSaGJ+Km3DFI7SCS/L/pCkOGf0qpsVjCaa2sffUn4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ylt2rBb/V5Ohr4mC/mNKydFbRQP1clmzso4n9vKYOZ5I/iX7E7LXfW0hZeuzXcsFvJpRV+ZTmL6Kmkwk54EOKZUF+AIRioR0eCCOQcLU294ykn/DX0VCdC20JGkrPP+tIKuqrQ3vVDu18jg7X/ddKeAwlMBbFoIQgqDQkHuVAdc= 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=c4/iv5pU; 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="c4/iv5pU" 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=4Nl3gS0QUrXTFXdXBLAhP3tCDZO9ar9+UJa2VZXcBSI=; b=c4/iv5pUGXan/JbeSdK5Y7o7mQ P5KX1VVikBMmy9jpRTAEuXtzJ3D4BS3+T4gfijGkBovWr4h31M6sD/Srs+jAG5LxbN0OWatNd9u1p I1AAVX/iWzTT+jPFGZHatqrfsTJ5NPcbXHWggQmibg8YgXLJ5zpFGH9IVwmTxRlGtQdr1pmOAVyNn AcDxDv1J4Js6tpHM32aPuVpNEBSHXk7XaZvaRKW/d3tt43o5ge8hvRCsOInazv80oHDO6eg+RZVFx aAs4dhCCZAgAZZevZoqOE2347XgFCvaic1lmW1t8kAfY4zW8bawJOTlxxy8k5k3yD8o5Pk/5hMxSy 6dI1neBg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:54088) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sNBQC-0006Yw-1N; Fri, 28 Jun 2024 14:13:48 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sNBQE-0006XI-3Y; Fri, 28 Jun 2024 14:13:50 +0100 Date: Fri, 28 Jun 2024 14:13:49 +0100 From: "Russell King (Oracle)" To: richard clark Cc: Steven Rostedt , Marc Zyngier , Mark Rutland , will@kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linus Torvalds Subject: Re: Will smp_call_function_single(cpu, ...) broadcast IPI to all other cpus? Message-ID: References: <86pls2isal.wl-maz@kernel.org> <20240627101207.0bbbead0@rorschach.local.home> 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: Sender: Russell King (Oracle) On Fri, Jun 28, 2024 at 06:21:25PM +0800, richard clark wrote: > The output is: > > insmod-1746 [000] dn.h1.. 928.400039: ipi_raise: > target_mask=00000000,000000ffe (Function call interrupts) > insmod-1746 [000] dn.h2.. 928.400042: > => trace_event_raw_event_ipi_raise > => smp_cross_call > => arch_send_call_function_single_ipi > => send_call_function_single_ipi I'm not sure whether the above is misproperly pasted or not, but if it is correct, it shows a problem. We can see from the first line that the target mask covers CPUs 1..11. However, the call chain is for arch_send_call_function_single_ipi(), which does: smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC); and cpumask_of(cpu) should only ever contain a single bit, and not multiple bits which the output above suggests it does! -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!