On 09/20/2011 09:45 AM, Johannes Weiner wrote:
This patch allows allocators to pass __GFP_WRITE when they know in advance that the allocated page will be written to and become dirty soon. The page allocator will then attempt to distribute those allocations across zones, such that no single zone will end up full of dirty, and thus more or less, unreclaimable pages. The global dirty limits are put in proportion to the respective zone's amount of dirtyable memory and allocations diverted to other zones when the limit is reached. For now, the problem remains for NUMA configurations where the zones allowed for allocation are in sum not big enough to trigger the global dirty limits, but a future approach to solve this can reuse the per-zone dirty limit infrastructure laid out in this patch to have dirty throttling and the flusher threads consider individual zones. Signed-off-by: Johannes Weiner<jweiner@xxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> The amount of work done in a __GFP_WRITE allocation looks a little daunting, but doing that a million times probably outweighs waiting on the disk even once, so... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>