From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m49244.qiye.163.com (mail-m49244.qiye.163.com [45.254.49.244]) (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 ED7BE33468C for ; Fri, 17 Apr 2026 15:52:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.254.49.244 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776441132; cv=none; b=BVPso/70P4X2g3BHpMd+u1WKmZEwokyIbTXVvFSDluoCx9T6L1uRXBa1bIC1Dm3DywukW7IHDMU5ix1beCB7SpvsTuB2h+ywbnNM1RwQathsK2HJls6eLdwRq2+nPbzalK5UbqiRYxy6+kUnPY1XOhBM+YdrjOlGBsaAnAWNfUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776441132; c=relaxed/simple; bh=JMgMMWX2dTVeZ32PbyMV7Kygd8OSLepd8Oy70oCiFr4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JPttHSiET/l6HPuAHEBkgKRcOJAu5/ExGffHFCRg5KBMuIpx/gKLl17iSGIdP9yyQHwf+aZy8TxyVDUsEIDXKcac0SRYAEWGlqj2FeZPC6KkTxCZ7gOHj7T9po8W576izPQ6hJUXJ6QtRluu1bxW2Mn5D5Tr4TmWANO+c7+0TkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=easystack.cn; spf=pass smtp.mailfrom=easystack.cn; arc=none smtp.client-ip=45.254.49.244 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=easystack.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=easystack.cn Received: from localhost.localdomain (unknown [IPV6:2409:8a20:ef7:a5b4:8810:8f74:8c26:2]) by smtp.qiye.163.com (Hmail) with ESMTP id 190e229f9; Fri, 17 Apr 2026 23:46:52 +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 2/3] mm/page_owner: add compact mode filter Date: Fri, 17 Apr 2026 23:46:37 +0800 Message-Id: <20260417154638.22370-3-zhen.ni@easystack.cn> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20260417154638.22370-1-zhen.ni@easystack.cn> References: <20260417154638.22370-1-zhen.ni@easystack.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0a9d9c1fa39c0229kunm7c3615e318e5a6 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWS1ZQUlXWQ8JGhUIEh9ZQVlDSB4ZVksZSk5KTB9KTB8eH1YVFAkWGhdVGRETFh oSFyQUDg9ZV1kYEgtZQVlJT0tCQUMaSUtBHh1MQRpOGU9BQ0NKS0FDHUxPQUMYSU1BSVlXWRYaDx IVHRRZQVlPS0hVSktJT09PSFVKS0tVSkJLS1kG Add compact mode functionality to reduce page_owner output size by printing only the stack handle instead of the full stack trace. Example output: Page allocated via order 0, mask 0x42800(GFP_NOWAIT|__GFP_COMP), pid 1, tgid 1 (systemd), ts 349667370 ns PFN 0xa00a2 type Unmovable Block 1280 type Unmovable Flags 0x33fffe0000004124(referenced|lru|active|private|node=3|zone=0| lastcpupid=0x1ffff) handle: 17432583 Charged to memcg / Compact mode significantly reduces output size while preserving all other page allocation information, making it easier to analyze large volumes of page owner data.The correspondence between handles and stack traces can be obtained through the show_stacks_handles interface. Signed-off-by: Zhen Ni --- mm/page_owner.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index 6811439bf9e4..214b58eef3d8 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -585,7 +585,14 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, migratetype_names[pageblock_mt], &page->flags); - ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0); + /* Compact mode: print handle instead of full stack trace */ + if (READ_ONCE(owner_filter.compact)) { + ret += scnprintf(kbuf + ret, count - ret, + "handle: %d\n", handle); + } else { + ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0); + } + if (ret >= count) goto err; @@ -980,6 +987,24 @@ static int page_owner_threshold_set(void *data, u64 val) DEFINE_SIMPLE_ATTRIBUTE(page_owner_threshold_fops, &page_owner_threshold_get, &page_owner_threshold_set, "%llu"); +static int page_owner_compact_get(void *data, u64 *val) +{ + *val = READ_ONCE(owner_filter.compact); + return 0; +} + +static int page_owner_compact_set(void *data, u64 val) +{ + if (val != 0 && val != 1) + return -EINVAL; + WRITE_ONCE(owner_filter.compact, val); + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(page_owner_compact_fops, + &page_owner_compact_get, + &page_owner_compact_set, "%lld"); + static int __init pageowner_init(void) { @@ -993,6 +1018,8 @@ static int __init pageowner_init(void) debugfs_create_file("page_owner", 0400, NULL, NULL, &page_owner_fops); filter_dir = debugfs_create_dir("page_owner_filter", NULL); + debugfs_create_file("compact", 0600, filter_dir, NULL, + &page_owner_compact_fops); dir = debugfs_create_dir("page_owner_stacks", NULL); debugfs_create_file("show_stacks", 0400, dir, -- 2.20.1