On Thu, Jun 16, 2016 at 05:42:11PM +0900, Sergey Senozhatsky wrote: > On (06/16/16 15:47), Minchan Kim wrote: > > > [..] > > > > > this is what I'm getting with the [zsmalloc: keep first object offset in struct page] > > > > > applied: "count:0 mapcount:-127". which may be not related to zsmalloc at this point. > > > > > > > > > > kernel: BUG: Bad page state in process khugepaged pfn:101db8 > > > > > kernel: page:ffffea0004076e00 count:0 mapcount:-127 mapping: (null) index:0x1 > > > > > > > > Hm, it seems double free. > > > > > > > > It doen't happen if you disable zram? IOW, it seems to be related > > > > zsmalloc migration? > > > > > > need to test more, can't confidently answer now. > > > > > > > How easy can you reprodcue it? Could you bisect it? > > > > > > it takes some (um.. random) time to trigger the bug. > > > I'll try to come up with more details. > > > > Could you revert [1] and retest? > > > > [1] mm/compaction: split freepages without holding the zone lock > > ok, so this is not related to zsmalloc. finally manged to reproduce > it. will fork a separate thread. The reason I mentioned [1] is that it seems to have a bug. isolate_freepages_block __isolate_free_page if(!zone_watermark_ok()) return 0; list_add_tail(&page->lru, freelist); However, the page is not isolated. Joonsoo? _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization