Hi, On RT kernel, When CONFIG_LOCK_STAT is enabled, trying to load the kdump kernel (kexec -p) causes a kernel panic. I have seen slightly varying backtraces, but I see general protection fault every time. Hardware: x86_64, 4CPUs, LS20 blade. Kernel: 2.6.23.1-rt11. I don't see this problem on non-rt kernels. Kernstopped custom tracer. general protection fault: 0000 [1] PREEMPT SMP CPU 3 Modules linked in: ipmi_devintf ipmi_si ipmi_msghandler autofs4 hidp rfcomm l2cap bluetooth sunrpc nf_conntrack_netbios_ns ipt_REJECT nf_conntrack_ipv4 xt_state iptable_filter ip_tables ip6t_REJECT xt_tcpudp ip6table_filter ip6_tables x_tables ipv6 dm_mirror dm_multipath dm_mod video output sbs dock battery ac parport_pc lp parport joydev sg amd_rng rtc_cmos i2c_amd756 k8temp shpchp i2c_core rtc_core tg3 hwmon serio_raw rtc_lib button mptspi mptscsih scsi_transport_spi mptbase sd_mod scsi_mod ext3 jbd ehci_hcd ohci_hcd uhci_hcd Pid: 3540, comm: kexec Not tainted 2.6.23.1-rt11 #2 RIP: 0010:[<ffffffff8025ae13>] [<ffffffff8025ae13>] __lock_acquire+0x6b2/0xca0 RSP: 0018:ffff8102118d7eb8 EFLAGS: 00010092 RAX: 0bbda08e8f9f3119 RBX: ffff8101fb4defd0 RCX: ffffffff80e31110 RDX: 0bbda08e8f9f3119 RSI: 000000000000000a RDI: 0000000000000001 RBP: ffff8102118d7f18 R08: 0000000000000002 R09: 0000000000000001 R10: ffffffff80275659 R11: fffffffffffff000 R12: 00000000000000e6 R13: ffff8101fb4de7c0 R14: 0000000000000000 R15: 00000000001225dc FS: 00002b55f6778b00(0000) GS:ffff810211fbb940(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000032fc494ff0 CR3: 00000001fbfa0000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kexec (pid: 3540, threadinfo ffff8101fb518000, task ffff8101fb4de7c0) Stack: 00000001b434a540 0000000000000002 0000000000000000 ffffffff8068dc90 ffffffff80234dd8 ffff8102118d7f00 000000000000000a 0000000000000046 ffffffff8068dc78 0000000000000003 ffffffff8068dc78 00000000001225dc Call Trace: <IRQ> [<ffffffff80234dd8>] wake_up_process+0x12/0x14 [<ffffffff8025b45f>] lock_acquire+0x5e/0x77 [<ffffffff80275659>] handle_edge_irq+0x29/0x158 [<ffffffff804a1690>] __spin_lock+0x35/0x62 [<ffffffff80275659>] handle_edge_irq+0x29/0x158 [<ffffffff8020e5d2>] do_IRQ+0x80/0xea [<ffffffff8020c4a6>] ret_from_intr+0x0/0xf <EOI> [<ffffffff8033b647>] copy_user_generic_string+0x17/0x40 [<ffffffff80267f74>] sys_kexec_load+0x501/0x5dd [<ffffffff8020f17a>] syscall_trace_enter+0x95/0x99 [<ffffffff8020c0f7>] tracesys+0xdc/0xe1 INFO: lockdep is turned off. Code: 48 8b 10 0f 18 0a 48 39 c8 75 e4 f0 ff 0d 1b 5a 39 00 79 0d RIP [<ffffffff8025ae13>] __lock_acquire+0x6b2/0xca0 RSP <ffff8102118d7eb8> Kernel panic - not syncing: Fatal exception Call Trace: <IRQ> [<ffffffff8023af69>] panic+0xaf/0x16e [<ffffffff802322d6>] task_rq_lock+0x42/0x74 [<ffffffff804a0e7c>] rt_spin_unlock+0x1e/0x50 [<ffffffff804a0e7c>] rt_spin_unlock+0x1e/0x50 [<ffffffff804a2de0>] oops_end+0x69/0x72 [<ffffffff8020d776>] die+0x4a/0x54 [<ffffffff804a3440>] do_general_protection+0x116/0x11f [<ffffffff80258281>] put_lock_stats+0x2b/0x2d [<ffffffff804a294d>] error_exit+0x0/0x96 [<ffffffff80275659>] handle_edge_irq+0x29/0x158 [<ffffffff8025ae13>] __lock_acquire+0x6b2/0xca0 [<ffffffff80234dd8>] wake_up_process+0x12/0x14 [<ffffffff8025b45f>] lock_acquire+0x5e/0x77 [<ffffffff80275659>] handle_edge_irq+0x29/0x158 [<ffffffff804a1690>] __spin_lock+0x35/0x62 [<ffffffff80275659>] handle_edge_irq+0x29/0x158 [<ffffffff8020e5d2>] do_IRQ+0x80/0xea [<ffffffff8020c4a6>] ret_from_intr+0x0/0xf <EOI> [<ffffffff8033b647>] copy_user_generic_string+0x17/0x40 [<ffffffff80267f74>] sys_kexec_load+0x501/0x5dd [<ffffffff8020f17a>] syscall_trace_enter+0x95/0x99 [<ffffffff8020c0f7>] tracesys+0xdc/0xe1 INFO: lockdep is turned off. Thanks, Sripathi. - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html