From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yisheng Xie Subject: Re: [PATCH RFC v2 4/4] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages Date: Thu, 9 Nov 2017 18:54:57 +0800 Message-ID: <9991dd10-8883-7c82-bb4e-8145ea2b7299@huawei.com> References: <1509099265-30868-1-git-send-email-xieyisheng1@huawei.com> <1509099265-30868-5-git-send-email-xieyisheng1@huawei.com> <04e4cb50-8cba-58af-1a5e-61e818cffa70@suse.cz> <4b08f1e9-5449-6ea2-e7da-65fe5f678683@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Christopher Lameter Cc: Vlastimil Babka , akpm@linux-foundation.org, mhocko@suse.com, mingo@kernel.org, rientjes@google.com, n-horiguchi@ah.jp.nec.com, salls@cs.ucsb.edu, linux-mm@kvack.org, linux-kernel@vger.kernel.org, tanxiaojun@huawei.com, linux-api@vger.kernel.org, Andi Kleen List-Id: linux-api@vger.kernel.org Hi Christopher, On 2017/11/8 23:02, Christopher Lameter wrote: > On Wed, 8 Nov 2017, Yisheng Xie wrote: > >> Another case is current process is *not* the same as target process, and >> when current process try to migrate pages of target process from old_nodes >> to new_nodes, the new_nodes should be a subset of target process cpuset. > > The caller of migrate_pages should be able to migrate the target process > pages anywhere the caller can allocate memory. If that is outside the > target processes cpuset then that is fine. Pagecache pages that are not > allocated by the target process already are not subject to the target > processes restriction. So this is not that unusual. So there is no need to check the restriction of target process cpuset, right? I hope that I do not miss anything :) Thanks Yisheng Xie > > . >