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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44917C433EF for ; Mon, 6 Dec 2021 03:17:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9EDFC6B007B; Sun, 5 Dec 2021 22:17:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 976196B007D; Sun, 5 Dec 2021 22:17:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7EF8C6B007E; Sun, 5 Dec 2021 22:17:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0206.hostedemail.com [216.40.44.206]) by kanga.kvack.org (Postfix) with ESMTP id 686E16B007B for ; Sun, 5 Dec 2021 22:17:30 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 247D68249980 for ; Mon, 6 Dec 2021 03:17:20 +0000 (UTC) X-FDA: 78885908640.07.0782BAE Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf09.hostedemail.com (Postfix) with ESMTP id 25A123000105 for ; Mon, 6 Dec 2021 03:17:22 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10189"; a="300624004" X-IronPort-AV: E=Sophos;i="5.87,290,1631602800"; d="scan'208";a="300624004" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2021 19:17:17 -0800 X-IronPort-AV: E=Sophos;i="5.87,290,1631602800"; d="scan'208";a="478972618" Received: from yhuang6-desk2.sh.intel.com ([10.239.159.50]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2021 19:17:15 -0800 From: Huang Ying To: Peter Zijlstra , Mel Gorman Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Mel Gorman , Greg Kroah-Hartman , Valentin Schneider , stable@vger.kernel.org Subject: [PATCH] numa balancing: remove some outdated document Date: Mon, 6 Dec 2021 11:16:45 +0800 Message-Id: <20211206031645.3412350-1-ying.huang@intel.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 25A123000105 X-Stat-Signature: c4xhr9g9aqzg3xk9gyqcwxtrkryp3b9t Authentication-Results: imf09.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf09.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 134.134.136.100) smtp.mailfrom=ying.huang@intel.com X-HE-Tag: 1638760642-982179 Content-Transfer-Encoding: quoted-printable 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: After commit 8a99b6833c88 ("sched: Move SCHED_DEBUG sysctl to debugfs"), some NUMA balancing sysctls enclosed with SCHED_DEBUG has been moved to debugfs. This patch removes the document for the sysctls to keep the document consistent with the code. Signed-off-by: "Huang, Ying" Fixes: 8a99b6833c88 ("sched: Move SCHED_DEBUG sysctl to debugfs") Cc: Mel Gorman Cc: Peter Zijlstra (Intel) Cc: Greg Kroah-Hartman Cc: Valentin Schneider Cc: stable@vger.kernel.org # since v5.13 --- Documentation/admin-guide/sysctl/kernel.rst | 46 +-------------------- 1 file changed, 1 insertion(+), 45 deletions(-) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/= admin-guide/sysctl/kernel.rst index 426162009ce9..d2679ea6936e 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -609,51 +609,7 @@ be migrated to a local memory node. The unmapping of pages and trapping faults incur additional overhead tha= t ideally is offset by improved memory locality but there is no universal guarantee. If the target workload is already bound to NUMA nodes then th= is -feature should be disabled. Otherwise, if the system overhead from the -feature is too high then the rate the kernel samples for NUMA hinting -faults may be controlled by the `numa_balancing_scan_period_min_ms, -numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms, -numa_balancing_scan_size_mb`_, and numa_balancing_settle_count sysctls. - - -numa_balancing_scan_period_min_ms, numa_balancing_scan_delay_ms, numa_ba= lancing_scan_period_max_ms, numa_balancing_scan_size_mb -=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D - - -Automatic NUMA balancing scans tasks address space and unmaps pages to -detect if pages are properly placed or if the data should be migrated to= a -memory node local to where the task is running. Every "scan delay" the = task -scans the next "scan size" number of pages in its address space. When th= e -end of the address space is reached the scanner restarts from the beginn= ing. - -In combination, the "scan delay" and "scan size" determine the scan rate= . -When "scan delay" decreases, the scan rate increases. The scan delay an= d -hence the scan rate of every task is adaptive and depends on historical -behaviour. If pages are properly placed then the scan delay increases, -otherwise the scan delay decreases. The "scan size" is not adaptive but -the higher the "scan size", the higher the scan rate. - -Higher scan rates incur higher system overhead as page faults must be -trapped and potentially data must be migrated. However, the higher the s= can -rate, the more quickly a tasks memory is migrated to a local node if the -workload pattern changes and minimises performance impact due to remote -memory accesses. These sysctls control the thresholds for scan delays an= d -the number of pages scanned. - -``numa_balancing_scan_period_min_ms`` is the minimum time in millisecond= s to -scan a tasks virtual memory. It effectively controls the maximum scannin= g -rate for each task. - -``numa_balancing_scan_delay_ms`` is the starting "scan delay" used for a= task -when it initially forks. - -``numa_balancing_scan_period_max_ms`` is the maximum time in millisecond= s to -scan a tasks virtual memory. It effectively controls the minimum scannin= g -rate for each task. - -``numa_balancing_scan_size_mb`` is how many megabytes worth of pages are -scanned for a given scan. - +feature should be disabled. =20 oops_all_cpu_backtrace =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --=20 2.30.2