From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992648AbcB0XEJ (ORCPT ); Sat, 27 Feb 2016 18:04:09 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:46230 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756778AbcB0XEH (ORCPT ); Sat, 27 Feb 2016 18:04:07 -0500 Date: Sat, 27 Feb 2016 18:04:03 -0500 (EST) Message-Id: <20160227.180403.2101360385050644823.davem@davemloft.net> To: peter@hurleysoftware.com Cc: eric.dumazet@gmail.com, edumazet@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, dmaengine@vger.kernel.org, john.ogness@linutronix.de, bigeasy@linutronix.de, akpm@linux-foundation.org Subject: Re: Softirq priority inversion from "softirq: reduce latencies" From: David Miller In-Reply-To: <56D20733.1000409@hurleysoftware.com> References: <56D1E8B6.6090003@hurleysoftware.com> <1456604037.648.29.camel@edumazet-ThinkPad-T530> <56D20733.1000409@hurleysoftware.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 27 Feb 2016 15:04:06 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Hurley Date: Sat, 27 Feb 2016 12:29:39 -0800 > Not really. softirq raised from interrupt context will always execute > on this cpu and not in ksoftirqd, unless load forces softirq loop abort. That guarantee never was specified. Or are you saying that by design, on a system under load, your UART will not function properly? Surely you don't mean that.