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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 874C4C433ED for ; Fri, 7 May 2021 23:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 334EF6135F for ; Fri, 7 May 2021 23:47:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230169AbhEGXs0 (ORCPT ); Fri, 7 May 2021 19:48:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:50000 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229970AbhEGXsZ (ORCPT ); Fri, 7 May 2021 19:48:25 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 63708B036; Fri, 7 May 2021 23:47:24 +0000 (UTC) From: Davidlohr Bueso To: a.darwish@linutronix.de Cc: bigeasy@linutronix.de, peterz@infradead.org, tglx@linutronix.de, shung-hsi.yu@suse.com, dave@stgolabs.net, linux-kernel@vger.kernel.org, Davidlohr Bueso Subject: [PATCH v2] seqlock,lockdep: Only check for preemption_disabled in non-rt Date: Fri, 7 May 2021 16:47:13 -0700 Message-Id: <20210507234713.86097-1-dave@stgolabs.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210507233951.78950-1-dave@stgolabs.net> References: <20210507233951.78950-1-dave@stgolabs.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This silences the writer hitting this nonsensical warning on PREEMPT_RT. Reported-by: Shung-Hsi Yu Signed-off-by: Davidlohr Bueso --- v2: Resending because I had left out some small comments I had meant to add. include/linux/seqlock.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index f61e34fbaaea..2ce3e1efc9a9 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -268,7 +268,9 @@ static inline bool __seqprop_preemptible(const seqcount_t *s) static inline void __seqprop_assert(const seqcount_t *s) { +#ifndef CONFIG_PREEMPT_RT lockdep_assert_preemption_disabled(); +#endif } #define __SEQ_RT IS_ENABLED(CONFIG_PREEMPT_RT) @@ -529,6 +531,8 @@ static inline void do_write_seqcount_begin_nested(seqcount_t *s, int subclass) * only if the seqcount write serialization lock is associated, and * preemptible. If readers can be invoked from hardirq or softirq * context, interrupts or bottom halves must be respectively disabled. + * The PREEMPT_RT case relies on the reader serializing via LOCK+UNLOCK, + * so the context is preemptible. */ #define write_seqcount_begin(s) \ do { \ -- 2.26.2