From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751897AbeEQKWS (ORCPT ); Thu, 17 May 2018 06:22:18 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:45539 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750938AbeEQKWR (ORCPT ); Thu, 17 May 2018 06:22:17 -0400 Date: Thu, 17 May 2018 12:22:14 +0200 From: Sebastian Andrzej Siewior To: linux-rt-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, Steven Rostedt Subject: [PATCH RT] sched: let softirq_count() return !0 if inside local_bh_disable()ed section Message-ID: <20180517102214.orea3ol6dj7wvpf5@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: NeoMutt/20180323 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I don't see a reason why softirq_count() shouldn't reflect the fact that we are within a local_bh_disable() section. I *think* it was done primary because in RT the softirq is slightly different (and preemptible) and it broke some of RCU's assumptions. I don't see any fallout with this change. Furthermore, all checks like "WARN_ON(!softirq_count())" will work and we can drop the workaround we currently have in the queue. Signed-off-by: Sebastian Andrzej Siewior --- include/linux/preempt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 0591df500e9d..d8c05a2626ca 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -91,7 +91,7 @@ # define softirq_count() (preempt_count() & SOFTIRQ_MASK) # define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) #else -# define softirq_count() (0UL) +# define softirq_count() (current->softirq_nestcnt) extern int in_serving_softirq(void); #endif -- 2.17.0