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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1CADAC54EE9 for ; Tue, 20 Sep 2022 17:26:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Wj1OGGGWuyur2qTQ+FC/G3/ac2zxgk3g9OgrTZV/LM8=; b=g0+1+WKtfs1/UT nfMQwOVXyGx+DaDR4gcJnZs2ux/aOYh2ftvvaTI5IWfuJL7Vzo/5OD9sMnYUyNsBZwhVnJe5f2QjM Cu0JehJ6td30pHcMxYy9KM0U+MWrWFrmJHEXezFBnpqKv9T0UewIXSSybeqmcA7vtEnZScMej5YUV 0qMJggc2rq5QIe1a8lOh0j6X4yJg8/3gQf4WLN+z+2zo859wqS8QEb6uOwkYeCGt16VnIU/kJzqQO 4FnOCAfWvFhdFVBxCF92geTa8gve7NEZQd5GaYxKboXC5CnpyhuWpKcxbqBu/E89refZPgkMIvYmc aekteitA6YZ3fLP1MYqA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oah0C-005R01-Ac; Tue, 20 Sep 2022 17:25:44 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oah05-005Qwf-OW for linux-arm-kernel@lists.infradead.org; Tue, 20 Sep 2022 17:25:39 +0000 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=si58QQXhDNbieptEuqD9NE5OtAupQBUx3heqJf4L0IM=; b=ovZOi3eVlQo6C9FCuiI2svp5aA 0hEzscMix3VP4E2tnqQr4aeb0OwXIl498daY0M0LTia3P9ZieH7aiD1060EJ1moZPdCeJiVyI8RjS SoziM0Vl09yoka3/iIXPhJb6RxShTje05C0ztn0/XtjBfHErTPH5jHp4tuL+NHbiivLJTD9UlcLk4 BjY9TjXK0i0crnsq6WWL7o4DjyXg+7ekcmYf1vv9n5KWun36ZNW7O+9JSlSRWuz57j/xOyDz5VlRq yB0YpHnFlZLzXegX0FagCmQQYpYsL31gNGjZvRJFjXL+8ZJeuucgxFu4lLlBTz7y+p8vRZuwwpKzC z5I7gL8g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:34420) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oagzz-0002Ht-LS; Tue, 20 Sep 2022 18:25:31 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1oagzx-0007UA-Cc; Tue, 20 Sep 2022 18:25:29 +0100 Date: Tue, 20 Sep 2022 18:25:29 +0100 From: "Russell King (Oracle)" To: Li Chen Cc: arnd bergmann , linux-arm-kernel Subject: Re: Why GICD_ITARGETSR is not used by Linux Message-ID: References: <183588fd5a7.1074ac6241209386.2442883306267550831@linux.beauty> <45d1a6b4-eb28-4392-84a3-d30a2f8e150a@www.fastmail.com> <1835a49844d.111e968dc1302721.8856919484302602882@linux.beauty> <1835b8bd957.c0097d5d1453526.2223557782083902488@linux.beauty> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1835b8bd957.c0097d5d1453526.2223557782083902488@linux.beauty> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220920_102537_821568_ACE7DFAE X-CRM114-Status: GOOD ( 12.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Sep 20, 2022 at 05:37:15PM +0200, Li Chen wrote: > Hi Russell, > > ---- On Tue, 20 Sep 2022 12:09:38 +0200 Russell King (Oracle) wrote --- > > On ARM, we don't have that. We have a thundering herd of CPUs if we > > set more than one CPU to process the interrupt, which is grossly > > inefficient. > > So, on arm chips with PCIe controller(s), we also rely on irqbalance to > distribute endpoints' legacy irq/MSI/MSIx? I think irqbalance 1.x was functional for all IRQs, not just PCIe. However, yes, doing it in userspace at this point is the best solution anyway, IMHO, as it is possible to create whatever policies one desires there - and what works for one workload may not be good for another workload. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel