Re: PROBLEM + POSS FIX: kernel stack overflow, xfs, many disks, heavy write load, 8k stack, x86-64

From: Chris Mason <chris.mason@oracle.com>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: Dave Chinner <david@fromorbit.com>,
	John Berthels <john@humyo.com>,
	linux-kernel@vger.kernel.org, Nick Gregory <nick@humyo.com>,
	Rob Sanderson <rob@humyo.com>,
	xfs@oss.sgi.com, linux-mm@kvack.org
Subject: Re: PROBLEM + POSS FIX: kernel stack overflow, xfs, many disks, heavy write load, 8k stack, x86-64
Date: Fri, 9 Apr 2010 14:11:08 -0400	[thread overview]
Message-ID: <20100409181108.GG13327@think> (raw)
In-Reply-To: <4BBF6C51.5030203@sandeen.net>

On Fri, Apr 09, 2010 at 01:05:05PM -0500, Eric Sandeen wrote:
> Chris Mason wrote:
> 
> > shrink_zone on my box isn't 500 bytes, but lets try the easy stuff
> > first.  This is against .34, if you have any trouble applying to .32,
> > just add the word noinline after the word static on the function
> > definitions.
> > 
> > This makes shrink_zone disappear from my check_stack.pl output.
> > Basically I think the compiler is inlining the shrink_active_zone and
> > shrink_inactive_zone code into shrink_zone.
> > 
> > -chris
> > 
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index 79c8098..c70593e 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -620,7 +620,7 @@ static enum page_references page_check_references(struct page *page,
> >  /*
> >   * shrink_page_list() returns the number of reclaimed pages
> >   */
> > -static unsigned long shrink_page_list(struct list_head *page_list,
> > +static noinline unsigned long shrink_page_list(struct list_head *page_list,
> 
> FWIW akpm suggested that I add:
> 
> /*
>  * Rather then using noinline to prevent stack consumption, use
>  * noinline_for_stack instead.  For documentaiton reasons.
>  */
> #define noinline_for_stack noinline
> 
> so maybe for a formal submission that'd be good to use.

Oh yeah, I forgot about that one.  If the patch actually helps we can
switch it.

-chris