From patchwork Thu Oct 28 14:33:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12590367 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F5CFC433F5 for ; Thu, 28 Oct 2021 14:33:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AEE1060F58 for ; Thu, 28 Oct 2021 14:33:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AEE1060F58 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 220B7940007; Thu, 28 Oct 2021 10:33:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A85C6B0071; Thu, 28 Oct 2021 10:33:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 04849940007; Thu, 28 Oct 2021 10:33:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id CE1FF6B006C for ; Thu, 28 Oct 2021 10:33:32 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 4220D82499A8 for ; Thu, 28 Oct 2021 14:33:32 +0000 (UTC) X-FDA: 78746089464.04.A7C8E74 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf16.hostedemail.com (Postfix) with ESMTP id 0FB19F0000B1 for ; Thu, 28 Oct 2021 14:33:25 +0000 (UTC) Date: Thu, 28 Oct 2021 16:33:27 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1635431609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=PSl0NIy2VMW9T/tsWtY+5ewcyWeEp5FwTJPmKNlUZiI=; b=Uzt4tZ1460rL45UE2ZRoMq/ZtRHaMmMRux2C0xQmTBbJEQVebKjr6kuXjxbNWZrnl1pHvN Vcs9tY4HznakaHcuZ2CV8ViACBIY0/FCS6f9oIQrboAvsiCpLeHVblPvx4otf33emrb18y D2NLmmwGY71dx7m8ceseoBfewUoXbbiu34SMt6xZUG0urmi1lneYE8Pnkrey9XyHnucMGy Z4jNX7lQdFNoZHgoRTBAvxFW1KdLUAPWnga6Fmam6dreahmjbMRrFtqc77P+fO0qIHa3xE UDkhNrO1IjD9WsPGY+PEA5pzSuV2nZguGLAugbPnWIXEXhuIstk3cIppbXKazw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1635431609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=PSl0NIy2VMW9T/tsWtY+5ewcyWeEp5FwTJPmKNlUZiI=; b=1G3S+gCObIUjEZj+lfe5xwQOcaZmX8IiGKVrvXrkfFf2uZxXQviJl+RUE/eBkvfGnwmv4m WwJoo7wFjuu7kRAg== From: Sebastian Andrzej Siewior To: Andrew Morton , Mel Gorman Cc: linux-mm@kvack.org, Vlastimil Babka , Peter Zijlstra , Thomas Gleixner Subject: [PATCH] mm: Disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT Message-ID: <20211028143327.hfbxjze7palrpfgp@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline X-Stat-Signature: dz6xm159m1p1ynkdbsynhypcfrg5h411 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=Uzt4tZ14; dkim=pass header.d=linutronix.de header.s=2020e header.b=1G3S+gCO; spf=pass (imf16.hostedemail.com: domain of bigeasy@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0FB19F0000B1 X-HE-Tag: 1635431605-707834 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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: Mel Gorman Signed-off-by: Sebastian Andrzej Siewior Acked-by: Mel Gorman Reviewed-by: David Hildenbrand --- init/Kconfig | 2 +- mm/Kconfig | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index edc0a0228f143..f83e7a0478f7c 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -911,7 +911,7 @@ 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 diff --git a/mm/Kconfig b/mm/Kconfig index c150a0c6fce2c..5c5508fafcec5 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -374,7 +374,7 @@ config NOMMU_INITIAL_TRIM_EXCESS config TRANSPARENT_HUGEPAGE bool "Transparent Hugepage Support" - depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE + depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT select COMPACTION select XARRAY_MULTI help