On 01/24/2014 05:03 PM, Johannes Weiner wrote: > The dirty_balance_reserve is an approximation of the fraction of free > pages that the page allocator does not make available for page cache > allocations. As a result, it has to be taken into account when > calculating the amount of "dirtyable memory", the baseline to which > dirty_background_ratio and dirty_ratio are applied. > > However, currently the reserve is subtracted from the sum of free and > reclaimable pages, which is non-sensical and leads to erroneous > results when the system is dominated by unreclaimable pages and the > dirty_balance_reserve is bigger than free+reclaimable. In that case, > at least the already allocated cache should be considered dirtyable. > > Fix the calculation by subtracting the reserve from the amount of free > pages, then adding the reclaimable pages on top. > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> -- All rights reversed -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>