On Mon, Nov 16, 2015 at 10:45:21AM +0900, Minchan Kim wrote: > During the test with MADV_FREE on kernel I applied your patches, > I couldn't see any problem. > > However, in this round, I did another test which is same one > I attached but a liitle bit different because it doesn't do > (memcg things/kill/swapoff) for testing program long-live test. Could you share updated test? And could you try to reproduce it on clean mmotm-2015-11-10-15-53? > With that, I encountered this problem. > > page:ffffea0000f60080 count:1 mapcount:0 mapping:ffff88007f584691 index:0x600002a02 > flags: 0x400000000006a028(uptodate|lru|writeback|swapcache|reclaim|swapbacked) > page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) > page->mem_cgroup:ffff880077cf0c00 > ------------[ cut here ]------------ > kernel BUG at mm/huge_memory.c:3340! > invalid opcode: 0000 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 1657 Comm: memhog Not tainted 4.3.0-rc5-mm1-madv-free+ #4 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > task: ffff88006b0f1a40 ti: ffff88004ced4000 task.ti: ffff88004ced4000 > RIP: 0010:[<ffffffff8114bf67>] [<ffffffff8114bf67>] split_huge_page_to_list+0x907/0x920 > RSP: 0018:ffff88004ced7a38 EFLAGS: 00010296 > RAX: 0000000000000021 RBX: ffffea0000f60080 RCX: ffffffff81830db8 > RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffffffff821df4d8 > RBP: ffff88004ced7ab8 R08: 0000000000000000 R09: ffff8800000bc560 > R10: ffffffff8163d880 R11: 0000000000014f25 R12: ffffea0000f60080 > R13: ffffea0000f60088 R14: ffffea0000f60080 R15: 0000000000000000 > FS: 00007f43d3ced740(0000) GS:ffff8800782e0000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ff1f6fcdb98 CR3: 000000004cf56000 CR4: 00000000000006a0 > Stack: > cccccccccccccccd ffffea0000f60080 ffff88004ced7ad0 ffffea0000f60088 > ffff88004ced7ad0 0000000000000000 ffff88004ced7ab8 ffffffff810ef9d0 > ffffea0000f60000 0000000000000000 0000000000000000 ffffea0000f60080 > Call Trace: > [<ffffffff810ef9d0>] ? __lock_page+0xa0/0xb0 > [<ffffffff8114c09c>] deferred_split_scan+0x11c/0x260 > [<ffffffff81117bfc>] ? list_lru_count_one+0x1c/0x30 > [<ffffffff81101333>] shrink_slab.part.42+0x1e3/0x350 > [<ffffffff81105daa>] shrink_zone+0x26a/0x280 > [<ffffffff81105eed>] do_try_to_free_pages+0x12d/0x3b0 > [<ffffffff81106224>] try_to_free_pages+0xb4/0x140 > [<ffffffff810f8a59>] __alloc_pages_nodemask+0x459/0x920 > [<ffffffff8111e667>] handle_mm_fault+0xc77/0x1000 > [<ffffffff8142718d>] ? retint_kernel+0x10/0x10 > [<ffffffff81033629>] __do_page_fault+0x189/0x400 > [<ffffffff810338ac>] do_page_fault+0xc/0x10 > [<ffffffff81428142>] page_fault+0x22/0x30 > Code: ff ff 48 c7 c6 f0 b2 77 81 4c 89 f7 e8 13 c3 fc ff 0f 0b 48 83 e8 01 e9 88 f7 ff ff 48 c7 c6 70 a1 77 81 4c 89 f7 e8 f9 c2 fc ff <0f> 0b 48 c7 c6 38 af 77 81 4c 89 e7 e8 e8 c2 fc ff 0f 0b 66 0f > RIP [<ffffffff8114bf67>] split_huge_page_to_list+0x907/0x920 > RSP <ffff88004ced7a38> > ---[ end trace c9a60522e3a296e4 ]--- I don't see how it's possible: call lock_page() just before split_huge_page() in deferred_split_scan(). > So, I reverted all MADV_FREE patches and chaged it with MADV_DONTNEED. > In this time, I saw below oops in this time. > If I miss somethings, please let me know it. > > ------------[ cut here ]------------ > kernel BUG at include/linux/swapops.h:129! Looks similar to what I fixed by inserting smp_wmb() just before clear_compound_head() in __split_huge_page_tail(). Do you have this in place? Like in last -mm tree? > Another hit: > > page:ffffea0000520080 count:2 mapcount:0 mapping:ffff880072b38a51 index:0x600002602 > flags: 0x4000000000048028(uptodate|lru|swapcache|swapbacked) > page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) > page->mem_cgroup:ffff880077cf0c00 > ------------[ cut here ]------------ > kernel BUG at mm/huge_memory.c:3306! The same as the first one: no idea. -- Kirill A. Shutemov -- 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>