On 04/29/2013 12:31 PM, Mel Gorman wrote:
A PageActive page is now added to the inactivate list. While this looks strange, I think it is sufficiently harmless that additional barriers to address the case is not justified. Unfortunately, while I never witnessed it myself, these parallel updates potentially trigger defensive DEBUG_VM checks on PageActive and hence they are removed by this patch.
Could this not cause issues with __page_cache_release, called from munmap, exit, truncate, etc.? Could the eventual skewing of active vs inactive numbers break page reclaim heuristics? I wonder if we would need to move to a scheme where the PG_active bit is always the authoritive one, and we never pass an overriding "lru" parameter to __pagevec_lru_add. Would memory ordering between SetPageLRU and testing for PageLRU be enough to then prevent the statistics from going off? -- 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>