From patchwork Sun Jan 30 21:46:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Clark Williams X-Patchwork-Id: 538407 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 D298BC433F5 for ; Sun, 30 Jan 2022 22:19:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347767AbiA3WTr (ORCPT ); Sun, 30 Jan 2022 17:19:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232281AbiA3WTr (ORCPT ); Sun, 30 Jan 2022 17:19:47 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6325C061714; Sun, 30 Jan 2022 14:19:45 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 55C2C60F56; Sun, 30 Jan 2022 22:19:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7992CC340E4; Sun, 30 Jan 2022 22:19:44 +0000 (UTC) X-Mailbox-Line: From 21c067c189901e2f7b368bc1ff6e7216a367c347 Mon Sep 17 00:00:00 2001 From: Clark Williams To: Steven Rostedt , Sebastian Andrzej Siewior Cc: Thomas Gleixner , linux-rt-users@vger.kernel.org, williams@redhat.com, linux-kernel@vger.kernel.org Date: Sun, 30 Jan 2022 15:46:27 -0600 Subject: [PATCH PREEMPT_RT 4.19 STABLE] rt: PREEMPT_RT safety net for backported patches Message-Id: <20220130221944.7992CC340E4@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org While doing some 4.19-rt cleanup work, I stumbled across the fact that parts of two backported patches were dependent on CONFIG_PREEMPT_RT, rather than the CONFIG_PREEMPT_RT_FULL used in 4.19 and earlier RT series. The commits in the linux-stable-rt v4.19-rt branch are: dad4c6a33bf4e mm: slub: Don't resize the location tracking cache on PREEMPT_RT e626b6f873f2c net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT Discussing this at the Stable RT maintainers meeting, Steven Rostedt suggested that we automagically select CONFIG_PREEMPT_RT if CONFIG_PREEMPT_RT_FULL is on, giving us a safety net for any subsequently backported patches. Here's my first cut at that patch. I suspect we'll need a similar patch for stable RT kernels < 4.19. Suggested-by: Steven Rostedt Signed-off-by: Clark Williams Acked-by: Sebastian Andrzej Siewior --- kernel/Kconfig.preempt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 306567f72a3e..951f58cbd652 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -6,6 +6,10 @@ config PREEMPT_RT_BASE bool select PREEMPT +config PREEMPT_RT + bool + default false + config HAVE_PREEMPT_LAZY bool @@ -80,6 +84,7 @@ config PREEMPT_RT_FULL depends on IRQ_FORCED_THREADING select PREEMPT_RT_BASE select PREEMPT_RCU + select PREEMPT_RT help All and everything