From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 3E01D6B004D for ; Thu, 2 Apr 2009 16:21:43 -0400 (EDT) Date: Thu, 2 Apr 2009 13:18:16 -0700 From: Andrew Morton Subject: Re: [RFC][PATCH] don't show pgoff of vma if vma is pure ANON (was Re: mmotm 2009-01-12-16-53 uploaded) Message-Id: <20090402131816.54724d4e.akpm@linux-foundation.org> In-Reply-To: <20090115114312.e42a0dba.kamezawa.hiroyu@jp.fujitsu.com> References: <200901130053.n0D0rhev023334@imap1.linux-foundation.org> <20090113181317.48e910af.kamezawa.hiroyu@jp.fujitsu.com> <496CC9D8.6040909@google.com> <20090114162245.923c4caf.kamezawa.hiroyu@jp.fujitsu.com> <20090115114312.e42a0dba.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: hugh@veritas.com, mikew@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, yinghan@google.com List-ID: On Thu, 15 Jan 2009 11:43:12 +0900 KAMEZAWA Hiroyuki wrote: > On Wed, 14 Jan 2009 14:08:35 +0000 (GMT) > Hugh Dickins wrote: > > > On Wed, 14 Jan 2009, KAMEZAWA Hiroyuki wrote: > > > Hmm, is this brutal ? > > > > > > == > > > Recently, it's argued that what proc/pid/maps shows is ugly when a > > > 32bit binary runs on 64bit host. > > > > > > /proc/pid/maps outputs vma's pgoff member but vma->pgoff is of no use > > > information is the vma is for ANON. > > > By this patch, /proc/pid/maps shows just 0 if no file backing store. > > > > > > Signed-off-by: KAMEZAWA Hiroyuki > > > --- > > > > Brutal, but sensible enough: revert to how things looked before > > we ever starting putting vm_pgoff to work on anonymous areas. > > > > I slightly regret losing that visible clue to whether an anonymous > > vma has ever been mremap moved. But have I ever actually used that > > info? No, never. > > > > I presume you test !vma->vm_file so the lines fit in, fair enough. > > But I think you'll find checkpatch.pl protests at "(!vma->vm_file)?" > > > > I dislike its decisions on the punctuation of the ternary operator > > - perhaps even more than Andrew dislikes the operator itself! > > Do we write a space before a question mark? no: nor before a colon; > > but I also dislike getting into checkpatch.pl arguments! > > > > While you're there, I'd also be inclined to make task_nommu.c > > use the same loff_t cast as task_mmu.c is using. > > > Ok, I'll try to update to reasonable style. > afaik this update never happened? Here's what I have at present: From: KAMEZAWA Hiroyuki Recently, it's argued that what proc/pid/maps shows is ugly when a 32bit binary runs on 64bit host. /proc/pid/maps outputs vma's pgoff member but vma->pgoff is of no use information is the vma is for ANON. With this patch, /proc/pid/maps shows just 0 if no file backing store. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki Cc: Mike Waychison Reported-by: Ying Han Cc: Hugh Dickins Signed-off-by: Andrew Morton --- fs/proc/task_mmu.c | 3 ++- fs/proc/task_nommu.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff -puN fs/proc/task_mmu.c~proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas +++ a/fs/proc/task_mmu.c @@ -220,7 +220,8 @@ static void show_map_vma(struct seq_file flags & VM_WRITE ? 'w' : '-', flags & VM_EXEC ? 'x' : '-', flags & VM_MAYSHARE ? 's' : 'p', - ((loff_t)vma->vm_pgoff) << PAGE_SHIFT, + (!vma->vm_file) ? 0 : + ((loff_t)vma->vm_pgoff) << PAGE_SHIFT, MAJOR(dev), MINOR(dev), ino, &len); /* diff -puN fs/proc/task_nommu.c~proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas fs/proc/task_nommu.c --- a/fs/proc/task_nommu.c~proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas +++ a/fs/proc/task_nommu.c @@ -143,7 +143,8 @@ static int nommu_vma_show(struct seq_fil flags & VM_WRITE ? 'w' : '-', flags & VM_EXEC ? 'x' : '-', flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', - (unsigned long long) vma->vm_pgoff << PAGE_SHIFT, + (!vma->vm_file) ? 0 : + (unsigned long long) vma->vm_pgoff << PAGE_SHIFT, MAJOR(dev), MINOR(dev), ino, &len); if (file) { _ -- 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