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Date: Thu, 4 Jun 2009 10:57:01 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Stefani Seibold <stefani@seibold.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>,
       Ingo Molnar <mingo@elte.hu>, Joerg Engel <joern@logfs.org>,
       Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [patch] procfs: provide stack information for threads
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On Thu, 04 Jun 2009 13:56:29 +0200 Stefani Seibold <stefani@seibold.net> wrote:

> 
> Am Donnerstag, den 04.06.2009, 04:37 -0700 schrieb Andrew Morton:
> > On Thu, 04 Jun 2009 13:23:48 +0200 Stefani Seibold <stefani@seibold.net> wrote:
> > >  - slime done
> > 
> > What's "slime"?
> > 
> 
> Sorry, that was a typo, should be "slim down".

heh, OK.  Good typo.

> > > +	for (i = vma->vm_start; i+PAGE_SIZE <= stkpage; i += PAGE_SIZE) {
> > > +
> > > +		page = follow_page(vma, i, 0);
> > > +
> > > +		if (!IS_ERR(page) && page)
> > 
> > Shouldn't this be !page?
> > 
> 
> No, this is correct... I walk through the top of vma to the first mapped
> page, this is the high water mark of the stack.

Ah, duh, OK.

> > > +					unsigned long stack_start;
> > > +
> > > +					stack_start =
> > > +						((struct proc_maps_private *)
> > > +						m->private)->task->stack_start;
> > 
> > I'd suggested a clearer/cleaner way of implementing this.
> > 
> 
> Sorry, i can not see a problem here. In your last posting you wrote
> thats okay! And i have no idea how to make this expression
> clearer/cleaner.

Add a new intermediate variable:
					unsigned long stack_start;
					struct proc_maps_private *pmp;

					pmp = m->private;
					stack_start = pmp->task->stack_start;