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. [ 5763.720268] kernel BUG at kernel/locking/rtmutex.c:1057! [ 5763.720273] invalid opcode: 0000 [#1] PREEMPT_RT SMP NOPTI [ 5763.721831] CPU: 1 PID: 25163 Comm: AudioIPC0 Kdump: loaded Tainted: G E 5.9.12-rt20-rt #18 [ 5763.722619] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 [ 5763.723545] RIP: 0010:rt_spin_lock_slowlock_locked+0x29b/0x2d0 [ 5763.724027] Code: 7f 0f 85 23 ff ff ff 41 8b 46 0c 85 c0 0f 85 17 ff ff ff 49 8b 06 a9 00 00 08 00 0f 84 09 ff ff ff e9 ff fe ff ff 0f 0b 0f 0b <0f> 0b 48 89 df e8 fb 00 84 ff e9 fe fe ff ff 48 8b 43 10 48 85 c0 [ 5763.725587] RSP: 0000:ffff9e5a41b1faa8 EFLAGS: 00010086 [ 5763.726016] RAX: 00000000ffffffdd RBX: ffff903f77c68080 RCX: 0000000000000001 [ 5763.726592] RDX: 0000000000000001 RSI: 0000000000000400 RDI: 0000000000000000 [ 5763.727166] RBP: ffff903eadc919a8 R08: 0000000000000000 R09: 00000000000217e9 [ 5763.727820] R10: ffff9e5a41b1f910 R11: 00000000000003f0 R12: ffff903eadc91100 [ 5763.728500] R13: ffff9e5a41b1fae8 R14: ffff903f76189480 R15: 0000000000000286 [ 5763.729090] FS: 00007fbd86074700(0000) GS:ffff903f77c40000(0000) knlGS:0000000000000000 [ 5763.729985] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5763.730435] CR2: 00007fbd6d844000 CR3: 000000021dcbc005 CR4: 00000000001706e0 [ 5763.731028] Call Trace: [ 5763.731243] rt_spin_lock_slowlock+0x40/0x60 [ 5763.731603] rt_spin_lock+0x45/0x50 [ 5763.731901] zs_map_object+0x103/0x3a0 [ 5763.732224] zswap_frontswap_load+0x10c/0x390 [ 5763.732596] __frontswap_load+0x6e/0xd0 [ 5763.732933] swap_readpage+0x88/0x240 [ 5763.733233] read_swap_cache_async+0x2e/0x40 [ 5763.733579] swap_cluster_readahead+0x202/0x290 [ 5763.733961] ? swapin_readahead+0x85/0x480 [ 5763.734307] swapin_readahead+0x85/0x480 [ 5763.734686] ? find_get_entry+0xab/0x130 [ 5763.735018] ? pagecache_get_page+0x30/0x2e0 [ 5763.735386] ? do_swap_page+0x390/0xb00 [ 5763.735712] do_swap_page+0x390/0xb00 [ 5763.736027] handle_mm_fault+0x8db/0x13b0 [ 5763.736370] exc_page_fault+0x335/0x630 [ 5763.736745] ? asm_exc_page_fault+0x8/0x30 [ 5763.737237] asm_exc_page_fault+0x1e/0x30 [ 5763.737594] RIP: 0033:0x7fbdae932e1f [ 5763.737901] Code: 17 e0 c5 f8 77 c3 48 3b 15 26 c3 25 00 0f 83 25 01 00 00 48 39 f7 72 0f 74 12 4c 8d 0c 16 4c 39 cf 0f 82 c5 01 00 00 48 89 d1 <f3> a4 c3 80 fa 10 73 17 80 fa 08 73 27 80 fa 04 73 33 80 fa 01 77 [ 5763.739533] RSP: 002b:00007fbd86072dd8 EFLAGS: 00010287 [ 5763.739980] RAX: 00007fbd6ca00dc0 RBX: 00007fbd86072fa0 RCX: 0000000000000040 [ 5763.740571] RDX: 0000000000001040 RSI: 00007fbd6d844000 RDI: 00007fbd6ca01dc0 [ 5763.741421] RBP: 00007fbd87ae9fc0 R08: 0000000000000000 R09: 0000000000000000 [ 5763.742031] R10: 0000000000000001 R11: 00007fbd6ca00000 R12: 00007fbd86072de8 [ 5763.742615] R13: 00007fbd86072df0 R14: 0000000000000208 R15: 00007fbd86073100 [ 5763.743204] Modules linked in: ebtable_filter(E) ebtables(E) uinput(E) fuse(E) xt_comment(E) nf_log_ipv6(E) nf_log_ipv4(E) nf_log_common(E) xt_LOG(E) xt_limit(E) rpcsec_gss_krb5(E) nfsv4(E) dns_resolver(E) nfs(E) nfs_ssc(E) fscache(E) nfnetlink_cthelper(E) nfnetlink(E) af_packet(E) iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) xt_pkttype(E) xt_tcpudp(E) ip6t_REJECT(E) ipt_REJECT(E) iptable_filter(E) bpfilter(E) ip6table_mangle(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) ip_tables(E) xt_conntrack(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) libcrc32c(E) ip6table_filter(E) ip6_tables(E) x_tables(E) joydev(E) intel_rapl_msr(E) intel_rapl_common(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) crypto_simd(E) snd_hda_codec_generic(E) cryptd(E) ledtrig_audio(E) glue_helper(E) virtio_balloon(E) snd_hda_intel(E) snd_intel_dspcfg(E) snd_hda_codec(E) snd_hda_core(E) snd_hwdep(E) snd_pcm(E) tiny_power_button(E) snd_timer(E) snd(E) 8139too(E) [ 5763.743239] soundcore(E) i2c_piix4(E) button(E) pcspkr(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sch_fq_codel(E) sunrpc(E) ext4(E) crc16(E) mbcache(E) jbd2(E) ata_generic(E) hid_generic(E) usbhid(E) ata_piix(E) virtio_console(E) virtio_blk(E) virtio_rng(E) qxl(E) drm_ttm_helper(E) ttm(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) fb_sys_fops(E) cec(E) crc32c_intel(E) uhci_hcd(E) ehci_pci(E) ahci(E) rc_core(E) ehci_hcd(E) virtio_pci(E) libahci(E) virtio_ring(E) serio_raw(E) 8139cp(E) drm(E) virtio(E) usbcore(E) mii(E) libata(E) floppy(E) qemu_fw_cfg(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) 1. box in box in box is cute, but not all that useful :)
