From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id C8F566B0055 for ; Wed, 14 Jan 2009 09:08:41 -0500 (EST) Date: Wed, 14 Jan 2009 14:08:35 +0000 (GMT) From: Hugh Dickins Subject: Re: [RFC][PATCH] don't show pgoff of vma if vma is pure ANON (was Re: mmotm 2009-01-12-16-53 uploaded) In-Reply-To: <20090114162245.923c4caf.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: 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> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Mike Waychison , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, "linux-mm@kvack.org" , yinghan@google.com List-ID: 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. Hugh > Index: mmotm-2.6.29-Jan13/fs/proc/task_mmu.c > =================================================================== > --- mmotm-2.6.29-Jan13.orig/fs/proc/task_mmu.c > +++ mmotm-2.6.29-Jan13/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); > > /* > Index: mmotm-2.6.29-Jan13/fs/proc/task_nommu.c > =================================================================== > --- mmotm-2.6.29-Jan13.orig/fs/proc/task_nommu.c > +++ mmotm-2.6.29-Jan13/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