From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.haak.id.au (mail.haak.id.au [172.105.183.32]) (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 C749E2F692A for ; Mon, 10 Nov 2025 08:24:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=172.105.183.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762763094; cv=none; b=Q5mb1vbGHrfUp+WjRp0X1u22Sh4qPTaZZGxBDdBNfcsbcW9smIQfbl9YeuaLxDfjPALclY4th0BR0lC4qSAbGdoPCpgj9hOYB0bEuexkZn2b2BrXqmN+CUi47Y/3LFhCaQHI4cVhwf72+7sjmHjjBwKSgZuytFd6xscbOEJlfqw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762763094; c=relaxed/simple; bh=NpCmVUJwh/xKBdJAggdydPdh5BDCLpa3XMmphcI6tEg=; h=Date:From:To:Subject:Message-ID:MIME-Version:Content-Type; b=fwzV3vR0LLJnFW3USYdhF14Ih5U7My7/3cbmIjN9tq4UP5cGLHvlrHUZZAkGG+xgW2lXziro3Pxq5cCwAMT3uFscMVBoFnaWS6Ec5iubvbolyukVd9k/HYRM9w0vUxt+q3DNYNkYvZgGthwGIOt1QHc5GipS+JCBCuCkC2b3dIc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=haak.id.au; spf=pass smtp.mailfrom=haak.id.au; dkim=pass (2048-bit key) header.d=haak.id.au header.i=@haak.id.au header.b=fOw69M0z; arc=none smtp.client-ip=172.105.183.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=haak.id.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=haak.id.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=haak.id.au header.i=@haak.id.au header.b="fOw69M0z" Received: from xps15mal (180-150-104-78.b49668.bne.static.aussiebb.net [180.150.104.78]) by mail.haak.id.au (Postfix) with ESMTPSA id BABED83228 for ; Mon, 10 Nov 2025 18:20:12 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=haak.id.au; s=202002; t=1762762812; bh=NpCmVUJwh/xKBdJAggdydPdh5BDCLpa3XMmphcI6tEg=; h=Date:From:To:Subject:From; b=fOw69M0zj0f54Kl3BwhUPFpoGTD8SleejLRWVlMLC7RxSQvGPGd9d87C1xoEeoJl8 Qt75C1jjF5mqFR0vJc2UlWE/G2R2zDDAa/D2NwC32UHPRKrn7p4Kxc6rAZS/tsXQWA rASJ9hChF227FRiZv59sFg2yajypVMXfgCugoVzl0h9Mn/2JPphBSQ/6JNCF75LbeY r3FfZi9wC/4EBXRq8r3l2ohqWQXCCk4fbxAy+4KCiBAeQ8v0zMsaLAN7YFbBhBHJi8 jjiNzF5BpETW00jqMw+h+b7vIhDwZUAODOMG8YTaCj6MQAJfvKduyGy4s+o6NYyXz0 3oLooyDjrM0+A== Date: Mon, 10 Nov 2025 18:20:08 +1000 From: Mal Haak To: linux-kernel@vger.kernel.org Subject: Possible memory leak in 6.17.7 Message-ID: <20251110182008.71e0858b@xps15mal> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hello, I have found a memory leak in 6.17.7 but I am unsure how to track it down effectively. I am running a server that has a heavy read/write workload to a cephfs file system. It is a VM. Over time it appears that the non-cache useage of kernel dynamic memory increases. The kernel seems to think the pages are reclaimable however nothing appears to trigger the reclaim. This leads to workloads getting killed via oomkiller. smem -wp output: Area Used Cache Noncache firmware/hardware 0.00% 0.00% 0.00% kernel image 0.00% 0.00% 0.00% kernel dynamic memory 88.21% 36.25% 51.96% userspace memory 9.49% 0.15% 9.34% free memory 2.30% 2.30% 0.00% free -h output: total used free shared buff/cache available Mem: 31Gi 3.6Gi 500Mi 4.0Mi 11Gi 27Gi Swap: 4.0Gi 179Mi 3.8Gi Reverting to the previous LTS fixes the issue smem -wp output: Area Used Cache Noncache firmware/hardware 0.00% 0.00% 0.00% kernel image 0.00% 0.00% 0.00% kernel dynamic memory 80.22% 79.32% 0.90% userspace memory 10.48% 0.20% 10.28% free memory 9.30% 9.30% 0.00% I am unsure of the best way to track down the memory usage. I have tried stopping the workload and unmounting the cephfs filesystem. As well as removing the ceph and network related kernel modules. I assume some kind of tracing would be a way to find the culprit, however I am unsure of the best way to do that. I can do a git bisect and am in the process of getting a test reproducer made for that. But if there is an easier way to do it I would happily do that. Just to note, slabtop looks normal and doesn't show the memory usage. Thanks in advance Mal