From nobody Thu Dec 25 10:30:03 2025 Received: from out-175.mta1.migadu.com (out-175.mta1.migadu.com [95.215.58.175]) (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 549C525579 for ; Thu, 18 Jan 2024 12:39:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705581571; cv=none; b=DRZ7hdUOlIOvQ/STKl+Gk5SCgGm9T1DMHCiYS/uqvJjaYFhTc/5VLl6yMAQry1A1nDuPjbBBp//lpfSaX0VAHrpoBNJ5JSlBdsyPlZJuq/+Ri2ELwFQESfPrwyzuSt311cF6bYXVzw7J7AnMgrXEMdkhaeXqam6/2eg1+huvllQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705581571; c=relaxed/simple; bh=hOV1vAKEslMDXnSKKyUL4RMeDVj1M1oqk023PSsPXZ8=; h=X-Report-Abuse:DKIM-Signature:From:To:Cc:Subject:Date:Message-Id: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding: X-Migadu-Flow; b=Cgu1JJDLzWXym5qhRF87pBIEsjx0gKNBioeaA2xnc16LcH+b4R+E9pn/vgnePwaB9LoWaVLgY1CeWCwBbbRIVLBHZ7PcZlkBHH5lYjwK+OGWwtS4bo5Aui5f7B3u4OcVvy1gaNk1IU9dzhJlxUePbZ1jUbvg0MiAuXjkUtkKCj8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=CBfV/dbd; arc=none smtp.client-ip=95.215.58.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="CBfV/dbd" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1705581568; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TzFCclyqcCZ/DPTkdiqBlpFX5oAyD0zr6O7wxsAo568=; b=CBfV/dbd2xHdE+F7YOmZ8GE2oRxwpthKTYpZaNj00rjrNcG/Z6lT98VVTzGw5xvY9Iwof6 dbCeWyIuDNqzO2dQE9ps3z2Qxk/A0VvAR8HDZp233bxQeP3YxsFW41WeXH4eB6WEwKUxc2 jA2LqaFNCxUtLsV24/vypYmZim4cKdU= From: Gang Li To: David Hildenbrand , David Rientjes , Mike Kravetz , Muchun Song , Andrew Morton , Tim Chen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, ligang.bdlg@bytedance.com, Gang Li Subject: [PATCH v4 3/7] padata: dispatch works on different nodes Date: Thu, 18 Jan 2024 20:39:07 +0800 Message-Id: <20240118123911.88833-4-gang.li@linux.dev> In-Reply-To: <20240118123911.88833-1-gang.li@linux.dev> References: <20240118123911.88833-1-gang.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" When a group of tasks that access different nodes are scheduled on the same node, they may encounter bandwidth bottlenecks and access latency. Thus, numa_aware flag is introduced here, allowing tasks to be distributed across different nodes to fully utilize the advantage of multi-node systems. Signed-off-by: Gang Li Tested-by: David Rientjes Reviewed-by: Muchun Song --- include/linux/padata.h | 3 +++ kernel/padata.c | 14 ++++++++++++-- mm/mm_init.c | 1 + 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/include/linux/padata.h b/include/linux/padata.h index 495b16b6b4d7..f79ccd50e7f4 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -137,6 +137,8 @@ struct padata_shell { * appropriate for one worker thread to do at once. * @max_threads: Max threads to use for the job, actual number may be less * depending on task size and minimum chunk size. + * @numa_aware: Dispatch jobs to different nodes. If a node only has memor= y but + * no CPU, dispatch its jobs to a random CPU. */ struct padata_mt_job { void (*thread_fn)(unsigned long start, unsigned long end, void *arg); @@ -146,6 +148,7 @@ struct padata_mt_job { unsigned long align; unsigned long min_chunk; int max_threads; + bool numa_aware; }; =20 /** diff --git a/kernel/padata.c b/kernel/padata.c index 179fb1518070..10eae3f59203 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -485,7 +485,8 @@ void __init padata_do_multithreaded(struct padata_mt_jo= b *job) struct padata_work my_work, *pw; struct padata_mt_job_state ps; LIST_HEAD(works); - int nworks; + int nworks, nid; + static atomic_t last_used_nid =3D ATOMIC_INIT(0); =20 if (job->size =3D=3D 0) return; @@ -517,7 +518,16 @@ void __init padata_do_multithreaded(struct padata_mt_j= ob *job) ps.chunk_size =3D roundup(ps.chunk_size, job->align); =20 list_for_each_entry(pw, &works, pw_list) - queue_work(system_unbound_wq, &pw->pw_work); + if (job->numa_aware) { + int old_node =3D atomic_read(&last_used_nid); + + do { + nid =3D next_node_in(old_node, node_states[N_CPU]); + } while (!atomic_try_cmpxchg(&last_used_nid, &old_node, nid)); + queue_work_node(nid, system_unbound_wq, &pw->pw_work); + } else { + queue_work(system_unbound_wq, &pw->pw_work); + } =20 /* Use the current thread, which saves starting a workqueue worker. */ padata_work_init(&my_work, padata_mt_helper, &ps, PADATA_WORK_ONSTACK); diff --git a/mm/mm_init.c b/mm/mm_init.c index 2c19f5515e36..549e76af8f82 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2231,6 +2231,7 @@ static int __init deferred_init_memmap(void *data) .align =3D PAGES_PER_SECTION, .min_chunk =3D PAGES_PER_SECTION, .max_threads =3D max_threads, + .numa_aware =3D false, }; =20 padata_do_multithreaded(&job); --=20 2.20.1