Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932408Ab3ICHYp (ORCPT ); Tue, 3 Sep 2013 03:24:45 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:4491 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1759742Ab3ICHYn (ORCPT ); Tue, 3 Sep 2013 03:24:43 -0400 X-IronPort-AV: E=Sophos;i="4.89,1012,1367942400"; d="scan'208";a="8388710" Message-ID: <52258EAB.8040002@cn.fujitsu.com> Date: Tue, 03 Sep 2013 15:24:27 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: Wanpeng Li CC: Andrew Morton , Joonsoo Kim , David Rientjes , KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" References: <1378191706-29696-1-git-send-email-liwanp@linux.vnet.ibm.com> <1378191706-29696-3-git-send-email-liwanp@linux.vnet.ibm.com> In-Reply-To: <1378191706-29696-3-git-send-email-liwanp@linux.vnet.ibm.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/03 15:22:35, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/03 15:22:36, Serialize complete at 2013/09/03 15:22:36 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1879 Lines: 59 On 09/03/2013 03:01 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); > > Signed-off-by: Wanpeng Li Reviewed-by: Zhang Yanfei > --- > mm/vmalloc.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index e3ec8b4..5368b17 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2562,6 +2562,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v) > if (!counters) > return; > > + /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ > + smp_rmb(); > + if (v->flags & VM_UNINITIALIZED) > + return; > + > memset(counters, 0, nr_node_ids * sizeof(unsigned int)); > > for (nr = 0; nr < v->nr_pages; nr++) > @@ -2590,11 +2595,6 @@ static int s_show(struct seq_file *m, void *p) > > v = va->vm; > > - /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ > - smp_rmb(); > - if (v->flags & VM_UNINITIALIZED) > - return 0; > - > seq_printf(m, "0x%pK-0x%pK %7ld", > v->addr, v->addr + v->size, v->size); > > -- Thanks. Zhang Yanfei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/