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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4FCFCCD13D3 for ; Thu, 30 Apr 2026 16:56:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B980D6B0096; Thu, 30 Apr 2026 12:56:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B48736B0098; Thu, 30 Apr 2026 12:56:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A85676B0099; Thu, 30 Apr 2026 12:56:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 972226B0096 for ; Thu, 30 Apr 2026 12:56:17 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 4772B121CEC for ; Thu, 30 Apr 2026 16:33:07 +0000 (UTC) X-FDA: 84715766814.29.60A2A37 Received: from mail-m825.xmail.ntesmail.com (mail-m825.xmail.ntesmail.com [156.224.82.5]) by imf12.hostedemail.com (Postfix) with ESMTP id E488340002 for ; Thu, 30 Apr 2026 16:33:04 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=easystack.cn; spf=pass (imf12.hostedemail.com: domain of zhen.ni@easystack.cn designates 156.224.82.5 as permitted sender) smtp.mailfrom=zhen.ni@easystack.cn ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777566785; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4q250BtEv4viv+ANI4nfZNkmuWeV+IpraVi9dMDXEkE=; b=tqJfjul8XPThQhLGJz9s0xvFLcmezgZJAKYMsrQo75LEyYHpNLxy4HNuD4+y4peI+eZk1x 7d5ENbDjTTerA6GoPfUNmLjaif/yuxH6luvYr4ojaeMFyCiQxEPSv0UL32v/2YPwoDO7S5 YmjHO4Be6XuYzLQmjB+wQgO6aH3vEh0= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=easystack.cn; spf=pass (imf12.hostedemail.com: domain of zhen.ni@easystack.cn designates 156.224.82.5 as permitted sender) smtp.mailfrom=zhen.ni@easystack.cn ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1777566785; a=rsa-sha256; cv=none; b=b/FGP6v9hIwPjYrpx2STDczsGMY3XOpoyYn6F/w6EWTmWdqnSpZUuqsbnc3fgz4IX7E/dI VRMzfn2gLxHBg0yx2/4FPKUlv/quSVNG390c0BjWFqq1tWPrNXQJDhZNxung1TdD2vMaZt sFRlKhP85DvnGCTiu31UhD5eXrlgZxo= Received: from localhost.localdomain (unknown [IPV6:2409:8a20:e24:8c24:8810:8f74:8c26:2]) by smtp.qiye.163.com (Hmail) with ESMTP id 199a96d50; Fri, 1 May 2026 00:33:00 +0800 (GMT+08:00) From: Zhen Ni To: akpm@linux-foundation.org, vbabka@kernel.org Cc: surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zhen Ni Subject: [PATCH v4 2/3] mm/page_owner: add NUMA node filter with nodelist support Date: Fri, 1 May 2026 00:32:46 +0800 Message-Id: <20260430163247.13628-3-zhen.ni@easystack.cn> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20260430163247.13628-1-zhen.ni@easystack.cn> References: <20260430163247.13628-1-zhen.ni@easystack.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0a9ddf3c8d010229kunm7d32d45d8a84 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVlDThkeVklJH0tMQ0tMSE4YGVYVFA kWGhdVGRETFhoSFyQUDg9ZV1kYEgtZQVlJT0tCQUMaSUtBHklPQUMYSU9BQ0NKS0FDHUxPQUMYSU 1BSVlXWRYaDxIVHRRZQVlPS0hVSktJT09PSFVKS0tVSkJLS1kG X-Stat-Signature: dxo4oa8kcn97edq7o1ysiobr7cinwg3t X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: E488340002 X-Rspam-User: X-HE-Tag: 1777566784-982256 X-HE-Meta: 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 cePZLUBK Mpm0BCpEhCgr3n4qC7yp9XUaW0Z//53+HzkV7nE2amieVp8NAaHbvaV0ES/oXSEc8CC8T/cWOqppQ3ZhajAHvGdd1YrFr4h9TfxUswcp9zrjsiWBXD6L1zRxoexeGkk6MIPPOsZ8uP4FCZA2OFRjsy3RJ7pdBLp+eii1k7ZI3lBLW+p4= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Add NUMA node filtering functionality to page_owner to allow filtering pages by specific NUMA node(s). This is useful for NUMA-aware memory allocation analysis and debugging. The filter supports flexible nodelist input formats: - Single node: echo "0" > nid - Multiple nodes: echo "0,2,3" > nid - Node range: echo "0-3" > nid - Mixed format: echo "0,2-4,7" > nid - Clear filter: echo > nid (empty string) The implementation uses nodemask_t for efficient multi-node filtering and nodelist_parse() for flexible input parsing. Empty input clears the filter. Note: Access to nid_mask uses plain load/store without locking because nodemask_t is too large (128 bytes) for READ_ONCE/WRITE_ONCE. This is safe for debug use: low-frequency changes and torn reads would only cause temporary inconsistency in debug output. Signed-off-by: Zhen Ni --- Changes in v4: - Remove "-1" support, use empty string to clear filter - Use strncpy_from_user() instead of copy_from_user() - Add concurrency safety documentation for nid_mask access - Rename fops to page_owner_nid_filter_fops for consistency Changes in v3: - Remove READ_ONCE/WRITE_ONCE for nodemask_t (fixes compilation errors) * nodemask_t is a large structure (128 bytes) that triggers compile-time asserts * Direct assignment is safe for this use case - Add comment explaining input length calculation formula * 6 bytes = ",NNNNN" (comma + 5-digit node number) - Simplify "-1" check using kstrtoint() instead of dual strcmp() - Move nodemask_t mask read outside PFN iteration loop for performance * Avoids 128-byte structure copy on each iteration Changes in v2: - Use nodemask_t instead of int to support multiple nodes - Implement nodelist_parse() to support flexible input formats * Single node: "0", "2" * Multiple nodes: "0,2,3" * Ranges: "0-3" * Mixed: "0,2-4,7" - Use %*pbl format for output (e.g., "0-2", "0,2-4,7") - Use dynamic memory allocation (kmalloc) to handle variable-length input - Follow cpuset's max_write_len pattern: (100 + 6 * MAX_NUMNODES) --- mm/page_owner.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) diff --git a/mm/page_owner.c b/mm/page_owner.c index 28766c854d02..68dacf01c822 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -67,10 +67,18 @@ static const char * const page_owner_print_mode_strings[] = { struct page_owner_filter { enum page_owner_print_mode print_mode; + /* + * Access uses plain load/store without locking. + * nodemask_t is too large (128 bytes) for READ_ONCE/WRITE_ONCE. + * Safe for debug use: low-frequency changes, torn reads only cause + * temporary inconsistency in debug output. + */ + nodemask_t nid_mask; }; static struct page_owner_filter owner_filter = { .print_mode = PAGE_OWNER_PRINT_FULL_STACK, + .nid_mask = NODE_MASK_NONE, }; static bool page_owner_enabled __initdata; @@ -687,6 +695,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) struct page_ext *page_ext; struct page_owner *page_owner; depot_stack_handle_t handle; + nodemask_t mask; if (!static_branch_unlikely(&page_owner_inited)) return -EINVAL; @@ -700,6 +709,8 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) pfn++; + mask = owner_filter.nid_mask; + /* Find an allocated page */ for (; pfn < max_pfn; pfn++) { /* @@ -732,6 +743,14 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) if (unlikely(!page_ext)) continue; + /* NUMA node filter using bitmask */ + if (!nodes_empty(mask)) { + int nid = page_to_nid(page); + + if (!node_isset(nid, mask)) + goto ext_put_continue; + } + /* * Some pages could be missed by concurrent allocation or free, * because we don't hold the zone lock. @@ -1054,6 +1073,72 @@ static const struct file_operations page_owner_print_mode_fops = { .llseek = default_llseek, }; +static ssize_t nid_filter_write(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) +{ + char *kbuf; + nodemask_t mask; + int ret; + + /* + * Limit input size to handle worst-case nodelist (all nodes). + * Worst case per node: ",NNNNN" (comma + 5-digit node number) = 6 bytes. + * Formula: 100 bytes overhead + 6 * MAX_NUMNODES + */ + if (count > (100 + 6 * MAX_NUMNODES)) + return -EINVAL; + + kbuf = kmalloc(count + 1, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + if (strncpy_from_user(kbuf, buf, count) < 0) { + ret = -EFAULT; + goto out_free; + } + kbuf[count] = '\0'; + + /* Support nodelist format like "0", "0,2", "0-3", or empty to clear */ + if (nodelist_parse(kbuf, mask)) { + ret = -EINVAL; + goto out_free; + } + + owner_filter.nid_mask = mask; + ret = count; + +out_free: + kfree(kbuf); + return ret; +} + +static int nid_filter_show(struct seq_file *m, void *v) +{ + nodemask_t mask = owner_filter.nid_mask; + + if (nodes_empty(mask)) + seq_puts(m, "\n"); + else + seq_printf(m, "%*pbl\n", nodemask_pr_args(&mask)); + + return 0; +} + +static int nid_filter_open(struct inode *inode, struct file *file) +{ + return single_open(file, nid_filter_show, NULL); +} + +static const struct file_operations page_owner_nid_filter_fops = { + .owner = THIS_MODULE, + .open = nid_filter_open, + .read = seq_read, + .llseek = seq_lseek, + .write = nid_filter_write, + .release = single_release, +}; + static int __init pageowner_init(void) { @@ -1069,6 +1154,8 @@ static int __init pageowner_init(void) filter_dir = debugfs_create_dir("page_owner_filter", NULL); debugfs_create_file("print_mode", 0600, filter_dir, NULL, &page_owner_print_mode_fops); + debugfs_create_file("nid", 0600, filter_dir, NULL, + &page_owner_nid_filter_fops); dir = debugfs_create_dir("page_owner_stacks", NULL); debugfs_create_file("show_stacks", 0400, dir, -- 2.20.1