Re: Warn when we run out of swap space (was Re: Misleading OOMmessages)

From: Pavel Machek
Date: Fri May 22 2009 - 10:56:47 EST


On Fri 2009-05-22 10:17:15, Christoph Lameter wrote:
>
> Subject: Warn if we run out of swap space
>
> Running out of swap space means that the evicton of anonymous pages may no longer
> be possible which can lead to OOM conditions.
>
> Print a warning when swap space first becomes exhausted.
>
> Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>

WARN_ONCE... will it mean a backtrace? That's quite an overkill for
something that is not a kernel fault (and where backtrace is useless).

But yes, I agree in principle.
Pavel

> @@ -412,6 +412,7 @@ swp_entry_t get_swap_page(void)
> nr_swap_pages++;
> noswap:
> spin_unlock(&swap_lock);
> + WARN_ONCE(1, "All of swap is in use. Some pages cannot be swapped out.");
> return (swp_entry_t) {0};
> }

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