On Thu, 2020-12-03 at 10:48 +0100, Sebastian Andrzej Siewior wrote: > On 2020-12-03 10:40:16 [+0100], Mike Galbraith wrote: > > In thread "scheduling while atomic in z3fold", I mentioned that of the > > three pool methods, only zbud did not explode. Below is the explosion > > encountered when zsmalloc is used in conjunction with runltp -f mm. As > > with the z3fold explosion, this one also seems to be highly repeatable, > > this from one of my full distro "my box plays russian dolls [1]" KVMs. > > great. > > > [ 5763.720268] kernel BUG at kernel/locking/rtmutex.c:1057! > … > > [ 5763.726016] RAX: 00000000ffffffdd RBX: ffff903f77c68080 RCX: 0000000000000001 > > That is a deadlock. Does lockdep say anything or does it disable the bug > from happening? The later, for the first time it did not explode. However... [ 458.195604] BUG: spinlock bad magic on CPU#1, oom01/9449 [ 458.195609] lock: 0xffff980db7c69560, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 458.195613] CPU: 1 PID: 9449 Comm: oom01 Kdump: loaded Tainted: G E 5.9.12-rt20-rt #19 [ 458.195615] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 [ 458.195616] Call Trace: [ 458.195617] dump_stack+0x77/0x97 [ 458.195633] do_raw_spin_lock+0x71/0xc0 [ 458.195644] _raw_spin_lock_irqsave+0x45/0x50 [ 458.195650] ? rt_spin_lock_slowlock+0x3a/0x70 [ 458.195652] rt_spin_lock_slowlock+0x3a/0x70 [ 458.195656] rt_spin_lock+0x46/0xc0 [ 458.195658] ? zswap_frontswap_store+0x26e/0xa50 [ 458.195665] zswap_frontswap_store+0x26e/0xa50 [ 458.195667] ? rt_mutex_futex_unlock+0x56/0x80 [ 458.195668] __frontswap_store+0x6e/0x100 [ 458.195670] swap_writepage+0x37/0x70 [ 458.195671] shmem_writepage+0x267/0x400 [ 458.195674] pageout+0xd2/0x400 [ 458.195677] shrink_page_list+0xa6e/0xbd0 [ 458.195679] shrink_inactive_list+0x216/0x620 [ 458.195683] shrink_lruvec+0x39f/0x5e0 [ 458.195689] ? shrink_node+0x237/0x6e0 [ 458.195694] shrink_node+0x237/0x6e0 [ 458.195697] do_try_to_free_pages+0xb9/0x400 [ 458.195698] try_to_free_pages+0xe6/0x3b0 [ 458.195701] __alloc_pages_slowpath.constprop.108+0x3f8/0x1090 [ 458.195705] __alloc_pages_nodemask+0x3f6/0x480 [ 458.195707] alloc_pages_vma+0x135/0x190 [ 458.195711] handle_mm_fault+0x87c/0x16f0 [ 458.195715] ? lockdep_hardirqs_on+0x79/0x100 [ 458.195718] exc_page_fault+0x343/0x720 [ 458.195720] ? asm_exc_page_fault+0x1e/0x30 [ 458.195722] ? asm_exc_page_fault+0x8/0x30 [ 458.195723] asm_exc_page_fault+0x1e/0x30 [ 458.195724] RIP: 0033:0x414300 [ 458.195726] Code: e8 d5 f5 fe ff 48 83 f8 ff 0f 84 9c 00 00 00 41 83 fd 02 48 89 c5 74 32 41 83 fd 03 74 74 49 63 c4 48 89 ea 66 0f 1f 44 00 00 <c6> 02 07 48 01 c2 48 89 d1 48 29 e9 48 39 cb 7f ef 31 c0 48 83 c4 [ 458.195730] RSP: 002b:00007f1e1d790ec0 EFLAGS: 00010206 [ 458.195731] RAX: 0000000000001000 RBX: 00000000c0000000 RCX: 00000000416a8000 [ 458.195731] RDX: 00007f1cdde38000 RSI: 00000000c0000000 RDI: 0000000000000000 [ 458.195732] RBP: 00007f1c9c790000 R08: ffffffffffffffff R09: 0000000000000000 [ 458.195732] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000001000 [ 458.195733] R13: 0000000000000001 R14: 0000000000000001 R15: 00007ffe1f97c860
