From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx187.postini.com [74.125.245.187]) by kanga.kvack.org (Postfix) with SMTP id 769276B0031 for ; Mon, 16 Sep 2013 20:18:45 -0400 (EDT) Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Sep 2013 05:48:42 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id E57D61258051 for ; Tue, 17 Sep 2013 05:48:46 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r8H0Km7634668714 for ; Tue, 17 Sep 2013 05:50:49 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r8H0IcEm009855 for ; Tue, 17 Sep 2013 05:48:39 +0530 Date: Tue, 17 Sep 2013 08:18:37 +0800 From: Wanpeng Li Subject: Re: [RESEND PATCH v5 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" Message-ID: <20130917001837.GA9692@hacker.(null)> Reply-To: Wanpeng Li References: <1379202342-23140-1-git-send-email-liwanp@linux.vnet.ibm.com> <1379202342-23140-3-git-send-email-liwanp@linux.vnet.ibm.com> <523776D4.4070402@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <523776D4.4070402@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, rientjes@google.com, zhangyanfei@cn.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi KOSAKI, On Mon, Sep 16, 2013 at 05:23:32PM -0400, KOSAKI Motohiro wrote: >On 9/14/2013 7:45 PM, Wanpeng Li wrote: >> Changelog: >> *v2 -> v3: revert commit d157a558 directly >> >> The VM_UNINITIALIZED/VM_UNLIST flag introduced by commit f5252e00(mm: avoid >> null pointer access in vm_struct via /proc/vmallocinfo) is used to avoid >> accessing the pages field with unallocated page when show_numa_info() is >> called. This patch move the check just before show_numa_info in order that >> some messages still can be dumped via /proc/vmallocinfo. This patch revert >> commit d157a558 (mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead >> of show_numa_info); > >Both d157a558 and your patch don't explain why your one is better. Yes, some >messages _can_ be dumped. But why should we do so? More messages can be dumped and original commit f5252e00(mm: avoid null pointer access in vm_struct via /proc/vmallocinfo) do that. > >And No. __get_vm_area_node() doesn't use __GFP_ZERO for allocating vm_area_struct. >dumped partial dump is not only partial, but also may be garbage. vm_struct is allocated by kzalloc_node. > >I wonder why we need to call setup_vmalloc_vm() _after_ insert_vmap_area. I think it's another topic. Fill vm_struct and set VM_VM_AREA flag. If I misunderstand your question? Regards, Wanpeng Li -- 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