Hi all, The scenario is 1 MDS i86_64 CentOS 4 2.6.9-42.EL_lustre.1.5.95smp 1 OSS i686 2.6.9-42.EL_lustre.1.5.95smp 1 client i686 2.6.9-42.EL_lustre.1.5.95smp mount lustre on client cd <lustre_dir> while [ 1 == 1 ] do echo 1 > test done netconsole log: 5> Unable to handle kernel NULL pointer dereference at virtual address 00000003 <5> printing eip: <5> c010c3fd <5> *pde = 2dfa0001 <5> Oops: 0000 [#1] <5> SMP <5> Modules linked in: osc(U) mgc(U) lustre(U) lov(U) lquota(U) mdc(U) ksocklnd( U) ptlrpc(U) obdclass(U) lnet(U) lvfs(U) libcfs(U) i915(U) nfsd(U) exportfs(U) l ockd(U) nfs_acl(U) parport_pc(U) lp(U) parport(U) netconsole(U) autofs4(U) i2c_d ev(U) i2c_core(U) sunrpc(U) dm_mirror(U) button(U) battery(U) ac(U) md5(U) ipv6( U) uhci_hcd(U) ehci_hcd(U) snd_intel8x0(U) snd_ac97_codec(U) snd_pcm_oss(U) snd_ mixer_oss(U) snd_pcm(U) snd_timer(U) snd_page_alloc(U) snd_mpu401_uart(U) snd_ra wmidi(U) snd_seq_device(U) snd(U) soundcore(U) e100(U) mii(U) floppy(U) ext3(U) jbd(U) dm_mod(U) ata_piix(U) libata(U) sd_mod(U) scsi_mod(U) <5> CPU: 0 <5> EIP: 0060:[<c010c3fd>] Tainted: GF VLI <5> EFLAGS: 00010002 (2.6.9-42.EL_lustre.1.5.95smp_dbg) <5> EIP is at profile_pc+0x1a/0x23 <5> eax: ffffffff ebx: c02df823 ecx: e5b0ff3c edx: c02df823 <5> esi: e5b0ff3c edi: e5b0ffc4 ebp: e5b0fefc esp: e5b0fef4 <5> ds: 007b es: 007b ss: 0068 <5> Process ldlm_bl_24 (pid: 5022, threadinfo=e5b0e000 task=f583b6b0) <5> Stack: e5b0ff3c 00000001 e5b0ff0c c01246d0 c03cd188 00000000 e5b0ff24 c01184 85 <5> e5b0ff3c e5b0e000 00000000 e5b0ffc4 e5b0ff34 c0118531 e5b0ff3c f5a6e2 c0 <5> ffffffff c02e16ae f5a6e2c0 00000000 f5a6e2c0 00000000 e5b0ffc4 ffffff ff <5> Call Trace: <5> [<c0106e40>] show_stack+0x76/0x7e <5> [<c0106f4f>] show_registers+0xf0/0x158 <5> [<c0107102>] die+0xe0/0x170 <5> [<c011c521>] do_page_fault+0x408/0x606 <5> [<c02e174b>] error_code+0x2f/0x38 <5> [<c01246d0>] profile_tick+0x3f/0x4f <5> [<c0118485>] smp_local_timer_interrupt+0x29/0xa4 <5> [<c0118531>] smp_apic_timer_interrupt+0x31/0x5d <5> [<c02e16ae>] apic_timer_interrupt+0x1a/0x20 <5> Code: 5e 5f 5d c3 55 a1 b8 08 33 c0 89 e5 ff 50 10 5d c3 55 89 e5 56 89 c6 5 3 8b 58 28 89 d8 e8 24 b2 02 00 85 c0 89 da 74 06 8b 46 14 <8b> 50 04 5b 89 d0 5 e 5d c3 55 b8 04 ed 39 c0 89 e5 56 53 89 cb <5> <0>Kernel panic - not syncing: Fatal exception in interrupt <5> handled_panic is 0 <5> LustreError: 5022:0:(tracefile.c:422:collect_pages_on_cpu()) ASSERTION(tcd ! = NULL) failed <5> LustreError: 5022:0:(linux-debug.c:130:lbug_with_loc()) LBUG <5> Lustre: 5022:0:(linux-debug.c:155:libcfs_debug_dumpstack()) showing stack fo r process 5022 <5> ldlm_bl_24 R running 6788 5022 1 5023 5021 (L-TLB) <5> e5b0e000 00000000 e5b0ffc4 e5b0ff34 c0118531 e5b0ff3c f5a6e2c0 ffffffff <5> c02e16ae f5a6e2c0 00000000 f5a6e2c0 00000000 e5b0ffc4 ffffffff 000000 00 <5> 0001007b e4d3007b ffffffef c02df823 00000060 00000246 f8dc3df7 ffffff ff <5> Call Trace: <5> [<c0106e40>] show_stack+0x76/0x7e <5> [<f8be1ad5>] lbug_with_loc+0x88/0xaf [libcfs] <5> Debug: sleeping function called from invalid context at mm/slab.c:2063 <5> in_atomic():1[expected: 0], irqs_disabled():0 <5> [<c0106e5d>] dump_stack+0x15/0x17 <5> [<c0121546>] __might_sleep+0x7d/0x87 <5> [<c0148d64>] kmem_cache_alloc+0x20/0x5b <5> [<c01218a5>] dup_task_struct+0x1f/0xd2 <5> [<c0122480>] copy_process+0x87/0xb65 <5> [<c0123056>] do_fork+0x91/0x197 <5> [<c0105286>] kernel_thread+0x67/0x6f <5> [<f8be560e>] libcfs_debug_dumplog+0xc9/0xff [libcfs] <5> bad: scheduling while atomic! <5> [<c0106e5d>] dump_stack+0x15/0x17 <5> [<c02de2ad>] schedule+0x2d/0x8db <5> [<f8be5626>] libcfs_debug_dumplog+0xe1/0xff [libcfs] <5> LustreError: dumping log to /tmp/lustre-log.1164817548.5022 <5> LustreError: 5109:0:(tracefile.c:422:collect_pages_on_cpu()) ASSERTION(tcd ! = NULL) failed <5> R running 7304 5109 1 5102 (L-TLB) <5> f8bf7ae0 f8bf7ae0 e5944000 00000000 00000000 00000000 f8be550b 0000139e <5> 00000000 f8be552a f8be5516 c0105219 0000139e 00000000 00000000 <5> Call Trace: <5> [<c0106e40>] show_stack+0x76/0x7e <5> [<f8be1ad5>] lbug_with_loc+0x88/0xaf [libcfs] <5> bad: scheduling while atomic! <5> [<c0106e5d>] dump_stack+0x15/0x17 <5> [<c02de2ad>] schedule+0x2d/0x8db <5> [<f8be5626>] libcfs_debug_dumplog+0xe1/0xff [libcfs] <5> LustreError: dumping log to /tmp/lustre-log.1164817548.5109 <5> bad: scheduling while atomic! <5> [<c0106e5d>] dump_stack+0x15/0x17 <5> [<c02de2ad>] schedule+0x2d/0x8db <5> [<c02df727>] rwsem_down_write_failed+0x142/0x161 <5> [<f8be16a9>] .text.lock.linux_tracefile+0x28/0x43 [libcfs]