Re: [PATCH] Warn if we run out of swap space

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 26 May 2009 10:23:36 -0400 (EDT)
Christoph Lameter <cl@linux.com> wrote:

> @@ -410,6 +412,11 @@ swp_entry_t get_swap_page(void)
>  	}
> 
>  	nr_swap_pages++;
> +	if (!out_of_swap_message_printed) {
> +		out_of_swap_message_printed = 1;
> +		printk(KERN_WARNING "All of swap is in use. Some pages "
> +			"cannot be swapped out.\n");
> +	}
>  noswap:
>  	spin_unlock(&swap_lock);
>  	return (swp_entry_t) {0};
> Index: linux-2.6/mm/vmscan.c
> ===================================================================
> --- linux-2.6.orig/mm/vmscan.c	2009-05-26 09:06:03.000000000 -0500
> +++ linux-2.6/mm/vmscan.c	2009-05-26 09:20:30.000000000 -0500
> @@ -1945,6 +1945,15 @@ out:
>  		goto loop_again;
>  	}
> 
> +	/*
> +	 * If we had an out of swap condition but things have improved then
> +	 * reset the flag so that we print the message again when we run
> +	 * out of swap again.
> +	 */
> +#ifdef CONFIG_SWAP
> +	if (out_of_swap_message_printed && !vm_swap_full())
> +		out_of_swap_message_printed = 0;
> +#endif
>  	return sc.nr_reclaimed;
>  }

I still worry that there may be usage patterns which will result in
this message coming out many times.

--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>