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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 2971DC7658D for ; Thu, 27 Feb 2020 14:35:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8E7324688 for ; Thu, 27 Feb 2020 14:35:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582814137; bh=LptIzUxwKjl42YG8Ni/qcMG8j5lOeHqwdiwER+neHwg=; h=From:To:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=xz+J2BJGh59gxdq97pHi9Lx+1B15wKSfYNnAgs2h50OALZnAdCNZCA4KbqbeSIy2b 1urLgTZWznAKrjnGctOWvPVJdUIxBg7RXoTTJGRMiWnu6kOSrrWjMzlTQd+G+k1fwE GZoARr/gJd3cvfiAtKtkzwVnUeYb8nPZ23FrWP5o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732547AbgB0Ofg (ORCPT ); Thu, 27 Feb 2020 09:35:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:44980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387481AbgB0OeA (ORCPT ); Thu, 27 Feb 2020 09:34:00 -0500 Received: from localhost.localdomain (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (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 0C747246AE; Thu, 27 Feb 2020 14:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582814039; bh=LptIzUxwKjl42YG8Ni/qcMG8j5lOeHqwdiwER+neHwg=; h=From:To:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=gKXVK5tsLaynaC4LSDA0PTu+6Nv76v34XRXpd9lX5QC8t2/uKms0CXxCfIDaNjXDY faWucMNZSnVJ7nZ5nJHK6KAUSRLrQpgYR6fqT4G5E4YE3qmzUIPpZ0KJ0p2sEFkkEM tGp4XGCO2ql2KN6QEGQm954UDmR35SisehS5BXFI= From: zanussi@kernel.org To: LKML , linux-rt-users , Steven Rostedt , Thomas Gleixner , Carsten Emde , John Kacur , Sebastian Andrzej Siewior , Daniel Wagner , Tom Zanussi Subject: [PATCH RT 04/23] x86: preempt: Check preemption level before looking at lazy-preempt Date: Thu, 27 Feb 2020 08:33:15 -0600 Message-Id: X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sebastian Andrzej Siewior v4.14.170-rt75-rc2 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit 19fc8557f2323c52b26561651ed4d51fc688a740 ] Before evaluating the lazy-preempt state it must be ensure that the preempt-count is zero. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tom Zanussi --- arch/x86/include/asm/preempt.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index f66708779274..afa0e42ccdd1 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -96,6 +96,8 @@ static __always_inline bool __preempt_count_dec_and_test(void) if (____preempt_count_dec_and_test()) return true; #ifdef CONFIG_PREEMPT_LAZY + if (preempt_count()) + return false; if (current_thread_info()->preempt_lazy_count) return false; return test_thread_flag(TIF_NEED_RESCHED_LAZY); -- 2.14.1