From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from invmail4.hynix.com (exvmail4.skhynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4965E21D5A2; Mon, 17 Mar 2025 08:24:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742199856; cv=none; b=AwXUF7XhgGSncZxrN4OPVE63kOofrMK8hO6SZMwi5tmr1eqsyYf2xnTJ/pZ1S8qHluKZjRKbQPh9WMSx68ef0YWZdu3REZRdfz645amtMumuL+FvCHddia0uQh5mxUU4uiF/N9VqAK6o5bNJ/L9oqF6u9BqblhNmFjOjYFHeYGo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742199856; c=relaxed/simple; bh=BiwCSc+UTvZ2qvigYc0vMmu6VSHo6eQ0Lf5xt4+jM54=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SH1VvZHldGj2dmjHY9RClZLxBCC1RZvdOL7NWBKAo0KQRD0p7QOl7ztbgDgSSm7HIvR9OPqjsfMGQPwgLpcAcXZz1L8FfllWh6Zt1U1a8pjvEJeKUQx6dj5ebnegWbwtu1WfLSH4P3gO3UVGBXKwljYSABw7t4rau7aARoVwglo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-681ff7000002311f-07-67d7dc2aa1fe From: Rakie Kim To: Gregory Price Cc: Rakie Kim , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, joshua.hahnjy@gmail.com, dan.j.williams@intel.com, ying.huang@linux.alibaba.com, kernel_team@skhynix.com, honggyu.kim@sk.com, yunjeong.mun@sk.com, Jonathan Cameron Subject: Re: [PATCH v2 1/4] mm/mempolicy: Fix memory leaks in mempolicy_sysfs_init() Date: Mon, 17 Mar 2025 17:24:00 +0900 Message-ID: <20250317082406.818-1-rakie.kim@sk.com> X-Mailer: git-send-email 2.48.1.windows.1 In-Reply-To: References: 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-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrGLMWRmVeSWpSXmKPExsXC9ZZnka7WnevpBg+OmVvMWb+GzWL61AuM Fj/vHme3WLXwGpvF8a3z2C3OzzrFYnF51xw2i3tr/rNarF6T4cDpsXPWXXaP7rbL7B4tR96y eize85LJY9OnSeweJ2b8ZvHY+dDS4/MmuQCOKC6blNSczLLUIn27BK6MV+0f2QqWcFWsP/eH rYHxL3sXIyeHhICJxLO7P1lg7IWznwPZHBxsAkoSx/bGgJgiAqoSbVfcuxi5OJgFHjJJ3Jox gRmkXFggRGLdrcVgY1iAat5PuAkW5xUwlni14TwrxEhNiYZL95hAbE4BM4m7l16A2UICPEA1 +xkh6gUlTs58AnYCs4C8RPPW2cwgyyQErrNJdHVOYYMYJClxcMUNlgmM/LOQ9MxC0rOAkWkV o1BmXlluYmaOiV5GZV5mhV5yfu4mRmBoL6v9E72D8dOF4EOMAhyMSjy8BuuvpQuxJpYVV+Ye YpTgYFYS4WXZcT1diDclsbIqtSg/vqg0J7X4EKM0B4uSOK/Rt/IUIYH0xJLU7NTUgtQimCwT B6dUA+OSm99cS875mFwQYlrHwRA4W//fC2tV3q8zfJ+ELGtujv1i5TpNhblW9cj2L2ErYtKm xdtYfT3c9eYcJ+tPQdMfl8QU7I8dP79y1gnOy40dGmFLr9T6LluYWfbgbJ/B5cboGaVLihM7 JE4eEvj/PHk9n2tKWc2UvPCsHP3PWrH37jYz/fWYcECJpTgj0VCLuag4EQDklfQQaQIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrALMWRmVeSWpSXmKPExsXCNUNNS1frzvV0g08PdC3mrF/DZjF96gVG i593j7NbfH72mtli1cJrbBbHt85jtzg89ySrxflZp1gsLu+aw2Zxb81/VotD156zWqxek2Hx e9sKNgdej52z7rJ7dLddZvdoOfKW1WPxnpdMHps+TWL3ODHjN4vHzoeWHt9ue3gsfvGByePz JrkArigum5TUnMyy1CJ9uwSujFftH9kKlnBVrD/3h62B8S97FyMnh4SAicTC2c9Zuhg5ONgE lCSO7Y0BMUUEVCXarrh3MXJxMAs8ZJK4NWMCM0i5sECIxLpbi8FaWYBq3k+4CRbnFTCWeLXh PCvESE2Jhkv3mEBsTgEzibuXXoDZQgI8QDX7GSHqBSVOznzCAmIzC8hLNG+dzTyBkWcWktQs JKkFjEyrGEUy88pyEzNzTPWKszMq8zIr9JLzczcxAsN5We2fiTsYv1x2P8QowMGoxMNrsP5a uhBrYllxZe4hRgkOZiURXpYd19OFeFMSK6tSi/Lji0pzUosPMUpzsCiJ83qFpyYICaQnlqRm p6YWpBbBZJk4OKUaGFc/C6494HwxtPZMhWbY1vJ5csYtB5pLIgWua00R/p66wMJO6Zblrse1 00ItFKOmfclcZjvvu9jGt4fPFO2Xqa9IeeVz6X+15izWqxWKP4OOvVd+0WEzN3Sf++YTb5g5 6hWkbLd9uKHzO29u0eWn98+13chyCl35ldUlaaf/Jqlwvf5JO7y7bZVYijMSDbWYi4oTAUP0 dDFjAgAA X-CFilter-Loop: Reflected On Fri, 14 Mar 2025 09:42:31 -0400 Gregory Price wrote: > On Fri, Mar 14, 2025 at 10:55:00AM +0000, Jonathan Cameron wrote: > > > > > > 1) allocate node_attrs and mempolicy_kobj up front and keep your > > > reordering, this lets us clean up allocations on failure before > > > kobject_init is called > > > > > > 2) after this remove all the other code and just let > > > mempolicy_kobj_release clean up node_attrs > > > > > > 3) Add a (%d) to the error message to differentiate failures > > > > Given how unlikely (and noisy) a memory allocation failure is, > > maybe just drop the printing at all in those paths - allowing > > early returns. > > > > The lifetime rules around node_attrs in here are making readability > > poor. It is implicitly owned by the mempolicy_kobj, but no direct association. > > Maybe just encapsulating the kobject in a structure that contains > > this as a [] array at the end. Then we end up with single allocation of > > stuff that is effectively one thing. > > > > Even better recommendation, lets do as Jonathan suggests. <3 > > ~Gregory Hi Gregory I will revise the next version based on Jonathan's feedback. Moreover, I'll separate this patch from the hotplug series and make it an independent patch. Rakie