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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F781C64E8A for ; Wed, 2 Dec 2020 11:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2593A20DD4 for ; Wed, 2 Dec 2020 11:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727329AbgLBL7I (ORCPT ); Wed, 2 Dec 2020 06:59:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:38192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725995AbgLBL7I (ORCPT ); Wed, 2 Dec 2020 06:59:08 -0500 From: Frederic Weisbecker Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: Thomas Gleixner , Peter Zijlstra Cc: LKML , Frederic Weisbecker , Tony Luck , Vasily Gorbik , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Christian Borntraeger , Fenghua Yu , Heiko Carstens Subject: [PATCH 5/5] irq: Call tick_irq_enter() inside HARDIRQ_OFFSET Date: Wed, 2 Dec 2020 12:57:32 +0100 Message-Id: <20201202115732.27827-6-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201202115732.27827-1-frederic@kernel.org> References: <20201202115732.27827-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that account_hardirq_enter() is called after HARDIRQ_OFFSET has been incremented, there is nothing left that prevents us from also moving tick_irq_enter() after HARDIRQ_OFFSET is incremented. The desired outcome is to remove the nasty hack that prevents softirqs from being raised through ksoftirqd instead of the hardirq bottom half. Also tick_irq_enter() then becomes appropriately covered by lockdep. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Tony Luck Cc: Fenghua Yu Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger --- kernel/softirq.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index b8f42b3ba8ca..d5bfd5e661fc 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -377,16 +377,12 @@ asmlinkage __visible void __softirq_entry __do_softirq(void) */ void irq_enter_rcu(void) { - if (is_idle_task(current) && !in_interrupt()) { - /* - * Prevent raise_softirq from needlessly waking up ksoftirqd - * here, as softirq will be serviced on return from interrupt. - */ - local_bh_disable(); + __irq_enter_raw(); + + if (is_idle_task(current) && (irq_count() == HARDIRQ_OFFSET)) tick_irq_enter(); - _local_bh_enable(); - } - __irq_enter(); + + account_hardirq_enter(current); } /** -- 2.25.1