From patchwork Thu Sep 30 10:37:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12527939 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64C48C433EF for ; Thu, 30 Sep 2021 10:38:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E76F615E0 for ; Thu, 30 Sep 2021 10:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350026AbhI3Kjr (ORCPT ); Thu, 30 Sep 2021 06:39:47 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:49346 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349928AbhI3Kjr (ORCPT ); Thu, 30 Sep 2021 06:39:47 -0400 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1632998283; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=gXKSd/eksGYlMXTl37jwPIp0QpmS4EnfQLz9qLhbL+U=; b=dZsaYk14rnWbCheFjm1+76wdyt/mIC1xLKu7Ir8lYv2GEWuYHjdnJHkBihfkAvgYGVv6QN X18KDfTlmlbwoKZSdlWru0djfrBi7o9/2ZeHTbe4b0Nq9uGz4n8WdptxtRXLrVozd+vrs0 +/Z73pr5RlgFacCx9nsDbnSgOgL+H8OqTGDSDpP4XqqyqdAIzoFOJW/bqdCvCZP6HPmyWi qJ8kjtfnYj93vUxBK5pind1qJcOJsoLEDtsw6mRqads1uS36IYTjXl0FfS+XcSLGepMDX6 wiQSuwSus6W7EUCYRwNRyAUAp17FZix4sOYqtj85v9Zbul5fAgesN0J8B2VEhA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1632998283; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=gXKSd/eksGYlMXTl37jwPIp0QpmS4EnfQLz9qLhbL+U=; b=Jo5akA/m700YnlHuygrlIKeSG5iI2vbZRNNbjYACd75zuZiXisT/Gkfnt6+ZyRgLYS+8IF F3MvWQI5ANOT+2AQ== To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Cc: Peter Zijlstra , Thomas Gleixner , Christoph Hellwig , Greg Kroah-Hartman , Sebastian Andrzej Siewior Subject: [PATCH] irq_poll: Use raise_softirq_irqoff() in cpu_dead notifier Date: Thu, 30 Sep 2021 12:37:54 +0200 Message-Id: <20210930103754.2128949-1-bigeasy@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org __raise_softirq_irqoff() adds a bit to the pending sofirq mask and this is it. The softirq won't be handled in a deterministic way but randomly when an interrupt fires and handles softirq in its irq_exit() routine or if something randomly checks and handles pending softirqs in the call chain before the CPU goes idle. Add a local_bh_disable/enable() around the IRQ-off section which will handle pending softirqs. Signed-off-by: Sebastian Andrzej Siewior --- lib/irq_poll.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/irq_poll.c b/lib/irq_poll.c index 2f17b488d58e1..2b9f797642f60 100644 --- a/lib/irq_poll.c +++ b/lib/irq_poll.c @@ -191,11 +191,13 @@ static int irq_poll_cpu_dead(unsigned int cpu) * If a CPU goes away, splice its entries to the current CPU * and trigger a run of the softirq */ + local_bh_disable(); local_irq_disable(); list_splice_init(&per_cpu(blk_cpu_iopoll, cpu), this_cpu_ptr(&blk_cpu_iopoll)); __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ); local_irq_enable(); + local_bh_enable(); return 0; }