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

Open Source and information security mailing list archives

Date:	Fri, 09 Apr 2010 13:05:05 -0500
From:	Eric Sandeen <sandeen@...deen.net>
To:	Chris Mason <chris.mason@...cle.com>,
	Dave Chinner <david@...morbit.com>,
	John Berthels <john@...yo.com>, linux-kernel@...r.kernel.org,
	Nick Gregory <nick@...yo.com>, Rob Sanderson <rob@...yo.com>,
	xfs@....sgi.com, linux-mm@...ck.org
Subject: Re: PROBLEM + POSS FIX: kernel stack overflow, xfs, many disks,	heavy
 write load, 8k stack, x86-64

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.

>  					struct scan_control *sc,
>  					enum pageout_io sync_writeback)
>  {
> @@ -1121,7 +1121,7 @@ static int too_many_isolated(struct zone *zone, int file,
>   * shrink_inactive_list() is a helper for shrink_zone().  It returns the number
>   * of reclaimed pages
>   */
> -static unsigned long shrink_inactive_list(unsigned long max_scan,
> +static noinline unsigned long shrink_inactive_list(unsigned long max_scan,
>  			struct zone *zone, struct scan_control *sc,
>  			int priority, int file)
>  {
> @@ -1341,7 +1341,7 @@ static void move_active_pages_to_lru(struct zone *zone,
>  		__count_vm_events(PGDEACTIVATE, pgmoved);
>  }
>  
> -static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
> +static noinline void shrink_active_list(unsigned long nr_pages, struct zone *zone,
>  			struct scan_control *sc, int priority, int file)
>  {
>  	unsigned long nr_taken;
> @@ -1504,7 +1504,7 @@ static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
>  		return inactive_anon_is_low(zone, sc);
>  }
>  
> -static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
> +static noinline unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
>  	struct zone *zone, struct scan_control *sc, int priority)
>  {
>  	int file = is_file_lru(lru);
> 
> _______________________________________________
> xfs mailing list
> xfs@....sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
> 

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