I think I find a new issue, for integrity of this mail thread, I reply to this mail.
It is a concurrence issue either, when duplicate store and reclaim concurrentlly. zswap entry x with offset A is already stored in zswap backend. Consider the following scenario: thread 0: reclaim entry x (get refcount, but not call zswap_get_swap_cache_page) thread 1: store new page with the same offset A, alloc a new zswap entry y. store finished. shrink_page_list() call __remove_mapping(), and now it is not in swap_cache thread 0: zswap_get_swap_cache_page called. old page data is added to swap_cache Now, swap cache has old data rather than new data for offset A. error will happen If do_swap_page() get page from swap_cache. -- 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/
