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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C76BDC433EF for ; Wed, 1 Dec 2021 20:44:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353125AbhLAUrU (ORCPT ); Wed, 1 Dec 2021 15:47:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352975AbhLAUoi (ORCPT ); Wed, 1 Dec 2021 15:44:38 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26D90C06175A; Wed, 1 Dec 2021 12:41:17 -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 sin.source.kernel.org (Postfix) with ESMTPS id 73FDFCE2105; Wed, 1 Dec 2021 20:41:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13EAFC53FD0; Wed, 1 Dec 2021 20:41:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638391275; bh=u7hDbDByWYfT0TX0W3OHC3WM8OBJ/lrCMsCnd08PHIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=bzqexLznTw7eifiMaUbFNhSjDXnaFMdYCRsBnL94R0vJXvOy1JIvLIGzFe9J8FIKF goDWWE5ZeTmV0sAMauilCwnZXxEAnFB1oOZZ4cb3ssIkD61QBwLNuH2FqxND2jv2WV lIvoltR27E8bdy/IECR3/ezQBwHvB684iiiHfqgEawIcjaibMht6KAf+BBqwzDHKrz 2dx+k7s4a5KqxQlhPTY8al2uM0O3btosQ0Ovxd+h5HI2U+BK2pTZK6WCWkP2pYDABy org2Owk/Fi5APfUyLfmjhU7II9nG9xbLM4SKijvuyspNqmdj6eewBiH4OFyLxHV73V CDHMht83/Fu6w== From: zanussi@kernel.org To: LKML , linux-rt-users , Steven Rostedt , Thomas Gleixner , Carsten Emde , John Kacur , Sebastian Andrzej Siewior , Daniel Wagner , Clark Williams , "Luis Claudio R. Goncalves" , Tom Zanussi Cc: stable-rt@vger.kernel.org, Mel Gorman Subject: [PATCH RT 4/8] mm: Disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT Date: Wed, 1 Dec 2021 14:41:04 -0600 Message-Id: <0421bbd936f2b617164726e47825ce243f0fa5ee.1638391253.git.zanussi@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sebastian Andrzej Siewior v5.4.161-rt67-rc1 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit aae93144898af113331668f53f80cb83f5a07360 ] TRANSPARENT_HUGEPAGE: There are potential non-deterministic delays to an RT thread if a critical memory region is not THP-aligned and a non-RT buffer is located in the same hugepage-aligned region. It's also possible for an unrelated thread to migrate pages belonging to an RT task incurring unexpected page faults due to memory defragmentation even if khugepaged is disabled. Regular HUGEPAGEs are not affected by this can be used. NUMA_BALANCING: There is a non-deterministic delay to mark PTEs PROT_NONE to gather NUMA fault samples, increased page faults of regions even if mlocked and non-deterministic delays when migrating pages. [Mel Gorman worded 99% of the commit description]. Link: https://lore.kernel.org/all/20200304091159.GN3818@techsingularity.net/ Link: https://lore.kernel.org/all/20211026165100.ahz5bkx44lrrw5pt@linutronix.de/ Cc: stable-rt@vger.kernel.org Cc: Mel Gorman Signed-off-by: Sebastian Andrzej Siewior Acked-by: Mel Gorman Link: https://lore.kernel.org/r/20211028143327.hfbxjze7palrpfgp@linutronix.de Signed-off-by: Tom Zanussi --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index 266802704c06..c733392fe237 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -769,7 +769,7 @@ config NUMA_BALANCING bool "Memory placement aware NUMA scheduler" depends on ARCH_SUPPORTS_NUMA_BALANCING depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY - depends on SMP && NUMA && MIGRATION + depends on SMP && NUMA && MIGRATION && !PREEMPT_RT help This option adds support for automatic NUMA aware memory/task placement. The mechanism is quite primitive and is based on migrating memory when -- 2.17.1