From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id C28DD6B0038 for ; Tue, 28 Feb 2017 20:17:23 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id d18so36996469pgh.2 for ; Tue, 28 Feb 2017 17:17:23 -0800 (PST) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id q18si3186241pge.19.2017.02.28.17.17.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Feb 2017 17:17:23 -0800 (PST) Subject: Re: [PATCH 0/5] mm: support parallel free of memory References: <20170224114036.15621-1-aaron.lu@intel.com> <20170228163947.cbd83e48dcb149c697b316cd@linux-foundation.org> From: Aaron Lu Message-ID: <31665668-9885-6045-a314-8c092800c739@intel.com> Date: Wed, 1 Mar 2017 09:17:26 +0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tim Chen , Ying Huang On 03/01/2017 08:43 AM, Dave Hansen wrote: > On 02/28/2017 04:39 PM, Andrew Morton wrote: >> Dumb question: why not do this in userspace, presumably as part of the >> malloc() library? malloc knows where all the memory is and should be >> able to kick off N threads to run around munmapping everything? > > One of the places we saw this happen was when an app crashed and was > exit()'ing under duress without cleaning up nicely. The time that it > takes to unmap a few TB of 4k pages is pretty excessive. Thanks Dave for the answer, I should have put this in the changelog(will do that in the next revision). Sorry about this Andrew, I hope Dave's answer clears things up about the patch's intention. Regards, Aaron -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org