On 19.07.2013 22:55, Johannes Weiner wrote:
The way the page allocator interacts with kswapd creates aging imbalances, where the amount of time a userspace page gets in memory under reclaim pressure is dependent on which zone, which node the allocator took the page frame from.#1 fixes missed kswapd wakeups on NUMA systems, which lead to some nodes falling behind for a full reclaim cycle relative to the other nodes in the system #3 fixes an interaction where kswapd and a continuous stream of page allocations keep the preferred zone of a task between the high and low watermark (allocations succeed + kswapd does not go to sleep) indefinitely, completely underutilizing the lower zones and thrashing on the preferred zone These patches are the aging fairness part of the thrash-detection based file LRU balancing. Andrea recommended to submit them separately as they are bugfixes in their own right.
I have the patch applied and under testing. So far, so good. It looks like it could finally fix the bug that I was chasing few months ago (nicely described in your bullet #3). But, few more days of testing will be needed before I can reach a quality verdict.
Good job! -- Zlatko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
