From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zps37.corp.google.com (zps37.corp.google.com [172.25.146.37]) by smtp-out.google.com with ESMTP id l8E5fwJH013805 for ; Fri, 14 Sep 2007 06:41:58 +0100 Received: from nf-out-0910.google.com (nfcd3.prod.google.com [10.48.105.3]) by zps37.corp.google.com with ESMTP id l8E5fuR5008308 for ; Thu, 13 Sep 2007 22:41:57 -0700 Received: by nf-out-0910.google.com with SMTP id d3so554337nfc for ; Thu, 13 Sep 2007 22:41:56 -0700 (PDT) Message-ID: Date: Thu, 13 Sep 2007 22:41:54 -0700 From: "Ken Chen" Subject: Re: [PATCH 1/5] hugetlb: Account for hugepages as locked_vm In-Reply-To: <20070913175905.27074.92434.stgit@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070913175855.27074.27030.stgit@kernel> <20070913175905.27074.92434.stgit@kernel> Sender: owner-linux-mm@kvack.org Return-Path: To: Adam Litke Cc: linux-mm@kvack.org, libhugetlbfs-devel@lists.sourceforge.net, Andy Whitcroft , Mel Gorman , Bill Irwin , Dave McCracken List-ID: On 9/13/07, Adam Litke wrote: > Hugepages allocated to a process are pinned into memory and are not > reclaimable. Currently they do not contribute towards the process' locked > memory. This patch includes those pages in the process' 'locked_vm' pages. On x86_64, hugetlb can share page table entry if multiple processes have their virtual addresses all lined up perfectly. Because of that, mm->locked_vm can go negative with this patch depending on the order of which process fault in hugetlb pages and which one unmaps it last. Have you checked all user of mm->locked_vm that a negative number won't trigger unpleasant result? - Ken -- 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