From patchwork Wed Nov 24 18:03:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 520084 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68F78C433F5 for ; Wed, 24 Nov 2021 18:03:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350453AbhKXSGx (ORCPT ); Wed, 24 Nov 2021 13:06:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:56362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350102AbhKXSGi (ORCPT ); Wed, 24 Nov 2021 13:06:38 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 931A96104F; Wed, 24 Nov 2021 18:03:28 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1mpwcB-0027uu-NR; Wed, 24 Nov 2021 13:03:27 -0500 Message-ID: <20211124180327.553861475@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 24 Nov 2021 13:03:11 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Daniel Wagner , Tom Zanussi , "Srivatsa S. Bhat" Subject: [PATCH RT 08/13] locking: Drop might_resched() from might_sleep_no_state_check() References: <20211124180303.574562279@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org 5.10.78-rt56-rc3 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior might_sleep_no_state_check() serves the same purpose as might_sleep() except it is used before sleeping locks are acquired and therefore does not check task_struct::state because the state is preserved. That state is preserved in the locking slow path so we must not schedule at the begin of the locking function because the state will be lost and not preserved at that time. Remove might_resched() from might_sleep_no_state_check() to avoid losing the state before it is preserved. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- include/linux/kernel.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2cff7554395d..6eb0ab994f4c 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -222,7 +222,7 @@ extern void __cant_migrate(const char *file, int line); do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) # define might_sleep_no_state_check() \ - do { ___might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) + do { ___might_sleep(__FILE__, __LINE__, 0); } while (0) /** * cant_sleep - annotation for functions that cannot sleep