Re: [PATCH 08/12] vmscan: Setup pagevec as late as possible inshrink_inactive_list()

[Andrew Morton]

On Mon, 14 Jun 2010 12:17:49 +0100
Mel Gorman <mel@xxxxxxxxx> wrote:

> shrink_inactive_list() sets up a pagevec to release unfreeable pages. It
> uses significant amounts of stack doing this. This patch splits
> shrink_inactive_list() to take the stack usage out of the main path so
> that callers to writepage() do not contain an unused pagevec on the
> stack.

You can get the entire pagevec off the stack - just make it a
static-to-shrink_inactive_list() pagevec-per-cpu.

Locking just requires pinning to a CPU.  We could trivially co-opt
shrink_inactive_list()'s spin_lock_irq() for that, but
pagevec_release() can be relatively expensive so it'd be sad to move
that inside spin_lock_irq().  It'd be better to slap a
get_cpu()/put_cpu() around the whole thing.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/