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=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 25434C63777 for ; Tue, 1 Dec 2020 00:14:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCEF4207F7 for ; Tue, 1 Dec 2020 00:14:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="dfd9hHOA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389087AbgLAAN5 (ORCPT ); Mon, 30 Nov 2020 19:13:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:52602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387960AbgLAAN4 (ORCPT ); Mon, 30 Nov 2020 19:13:56 -0500 Received: from localhost.localdomain (mtl93-h04-176-174-252-224.dsl.sta.abo.bbox.fr [176.174.252.224]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D90FE2086A; Tue, 1 Dec 2020 00:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606781571; bh=SpjewY+zCUd4+dIAcXesrctaRe/IkPPUnJz7GEMao2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dfd9hHOAZSK0sLC1HBkPzasfm9b+ZwRu8a+W9xEZcYl4GT86DqG4CIswUBjk9BNKQ REe1bmdsTd0JP3lbTKBW7fDvIzkHn8W24wFj1OCYm2FZ2/BJQmXEqLDgnyk9TQM+Lh /IGUsnIhKuFxx9jUPKRCpm251vAfaslgRC4ecRU0= From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Frederic Weisbecker , Tony Luck , Peter Zijlstra , 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: Tue, 1 Dec 2020 01:12:26 +0100 Message-Id: <20201201001226.65107-6-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201201001226.65107-1-frederic@kernel.org> References: <20201201001226.65107-1-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_irq_enter_time() 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 24254c41bb7c..447ee4d6fe4d 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_irq_enter_time(current); } /** -- 2.25.1