Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754247AbeALFgH (ORCPT + 1 other); Fri, 12 Jan 2018 00:36:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:58342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753224AbeALFgG (ORCPT ); Fri, 12 Jan 2018 00:36:06 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A99A21722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=frederic@kernel.org From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Levin Alexander , Peter Zijlstra , Linus Torvalds , Hannes Frederic Sowa , "Paul E . McKenney" , Wanpeng Li , Dmitry Safonov , Thomas Gleixner , Eric Dumazet , Radu Rendec , Ingo Molnar , Stanislaw Gruszka , Paolo Abeni , Rik van Riel , Andrew Morton , David Miller Subject: [RFC PATCH 0/2] softirq: Per vector threading Date: Fri, 12 Jan 2018 06:35:52 +0100 Message-Id: <1515735354-19279-1-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: So this is a first shot to implement what Linus suggested. To summarize: when a softirq vector is stormed and needs more time than what IRQ tail can offer, the whole softirq processing is offloaded to ksoftirqd. But this has an impact on other softirq vectors that are then subject to scheduler latencies. So the softirqs time limits is now per vector and only the vectors that get stormed are offloaded to a thread (workqueue). This is in a very Proof of concept state. It doesn't even boot successfully once in a while. So I'll do more debugging tomorrow (today in fact) but you get the big picture. It probably won't come free given the clock reads around softirq callbacks. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git softirq/poc HEAD: 0e982634115283710d0801048e5a316def26f31d Thanks, Frederic --- Frederic Weisbecker (2): softirq: Account time and iteration stats per vector softirq: Per vector thread deferment kernel/softirq.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 114 insertions(+), 9 deletions(-)