From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2519E35972 for ; Thu, 8 May 2025 00:26:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746663971; cv=none; b=Lb9jJv2AOLIUDcu2+cWbO+GRNUKW4cwZ1AJsHR3GHyF7OaD3cVfkkS4ldZDQPVw5RT2XuuKICA2jlCuO+z9v/u4N6CWRbn9ZX66n/0W/0eLoogieH03uIb0yp0UGgN6O97mtA/ZjePrOUaeB0OvkS9Loum5p/AuJe4vn1tBsEXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746663971; c=relaxed/simple; bh=WU37a7a3ruLaIRqZtgEZnsoG5OFrwV3DLx7VxOciFvs=; h=Date:To:From:Subject:Message-Id; b=JpT/lUlvHIFLXli5FBeiC+GJUyDSS8fiQQKtBMfEiH8jELhglPL2K+X/xfGwU71vqgwYQQfmGwPwm8BDwZcBvUhgTYa4nnMaBbKuHSmXDFNr0kIUpurh2iPz7KeQNP7PAHsEwYPsTIYghQHP0V4MIcSa4QmFP/ON7aHEafdxvYs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=miMgaYYQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="miMgaYYQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52AC5C4CEE2; Thu, 8 May 2025 00:26:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1746663969; bh=WU37a7a3ruLaIRqZtgEZnsoG5OFrwV3DLx7VxOciFvs=; h=Date:To:From:Subject:From; b=miMgaYYQ4QJtys8jC51lSd2Af9CCdczdX4qlFHSOy2u11EqX6nNy6erCDGLaOr7lO M4dtcu071vPbuoQObMX7J0sNscN+nv5a6BcOHxrAzk9cQ1jilTK88RNL5aCmn0LQJA IX/oD3SY/Pgw43/MHKXldH/+fJusQHoGeMZMA18o= Date: Wed, 07 May 2025 17:26:08 -0700 To: mm-commits@vger.kernel.org,yu.c.chen@intel.com,vineethr@linux.ibm.com,tj@kernel.org,tim.c.chen@intel.com,shakeel.butt@linux.dev,roman.gushchin@linux.dev,peterz@infradead.org,muchun.song@linux.dev,mkoutny@suse.com,mingo@redhat.com,mhocko@kernel.org,mgorman@suse.de,kprateek.nayak@amd.com,hannes@cmpxchg.org,corbet@lwn.net,Ayush.jain3@amd.com,aubrey.li@intel.com,libo.chen@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: + sched-numa-fix-task-swap-by-skipping-kernel-threads.patch added to mm-new branch Message-Id: <20250508002609.52AC5C4CEE2@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: sched/numa: fix task swap by skipping kernel threads has been added to the -mm mm-new branch. Its filename is sched-numa-fix-task-swap-by-skipping-kernel-threads.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/sched-numa-fix-task-swap-by-skipping-kernel-threads.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Libo Chen Subject: sched/numa: fix task swap by skipping kernel threads Date: Wed, 7 May 2025 19:17:15 +0800 Patch series "sched/numa: add statistics of numa balance task migration", v4. Introduce task migration and swap statistics in the following places: /sys/fs/cgroup/{GROUP}/memory.stat /proc/{PID}/sched /proc/vmstat These statistics facilitate a rapid evaluation of the performance and resource utilization of the target workload. This patch (of 2): Task swapping is triggered when there are no idle CPUs in task A's preferred node. In this case, the NUMA load balancer chooses a task B on A's preferred node and swaps B with A. This helps improve NUMA locality without introducing load imbalance between nodes. In the current implementation, B's NUMA node preference is not mandatory, and it aims not to increase load imbalance. That is to say, a kernel thread might be chosen as B. However, kernel threads are not supposed to be covered by NUMA balancing because NUMA balancing only considers user pages via VMAs. Fix this by not considering kernel threads as swap targets in task_numa_compare(). This can be extended beyond kernel threads in the future by checking if a swap candidate has a valid NUMA preference through checking the candidate's numa_preferred_nid and numa_faults. For now, keep the code simple. Link: https://lkml.kernel.org/r/cover.1746611892.git.yu.c.chen@intel.com Link: https://lkml.kernel.org/r/a541cdf9b97f523f6b8067271847a986db5ba768.1746611892.git.yu.c.chen@intel.com Signed-off-by: Libo Chen Signed-off-by: Chen Yu Suggested-by: Michal Koutny Tested-by: Ayush Jain Cc: Aubrey Li Cc: "Chen, Tim C" Cc: Ingo Molnar Cc: Johannes Weiner Cc: Jonathan Corbet Cc: K Prateek Nayak Cc: Madadi Vineeth Reddy Cc: Mel Gorman Cc: Michal Hocko Cc: Muchun Song Cc: Peter Zijlstra (Intel) Cc: Roman Gushchin Cc: Shakeel Butt Cc: Tejun Heo Signed-off-by: Andrew Morton --- kernel/sched/fair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/sched/fair.c~sched-numa-fix-task-swap-by-skipping-kernel-threads +++ a/kernel/sched/fair.c @@ -2273,7 +2273,8 @@ static bool task_numa_compare(struct tas rcu_read_lock(); cur = rcu_dereference(dst_rq->curr); - if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur))) + if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur) || + !cur->mm)) cur = NULL; /* _ Patches currently in -mm which might be from libo.chen@oracle.com are sched-numa-skip-vma-scanning-on-memory-pinned-to-one-numa-node-via-cpusetmems.patch sched-numa-add-tracepoint-that-tracks-the-skipping-of-numa-balancing-due-to-cpuset-memory-pinning.patch sched-numa-fix-task-swap-by-skipping-kernel-threads.patch