Hi Peter and Thomas, LKP found a bug, and it was bisected to my rewrite patch: http://article.gmane.org/gmane.linux.kernel/1818393/
But I really don't have a clue about why the patch can introduce such a bug, as the patch does not modify anything related. Or maybe the bug could be indirectly triggerd, just don't know how. To confirm it is not a false positive, we are rebasing the patch to 3.18-rc3 to try to reproduce it, it is now ongoing. In addition, I noticed this thread about the same symptom: http://thread.gmane.org/gmane.linux.kernel/1819348. Thomas should already have a fix to this. Right? Thanks, Yuyang On Tue, Nov 04, 2014 at 12:29:22PM +0800, kernel test robot wrote: > git://bee.sh.intel.com/git/ydu19/linux for-lkp > commit 6fe1f1b9b13f9fd76d1230944482ee5bf2832252 ("sched: Remove task and > group entity load_avg when they are dead") > > +---------------------------------------------------------------+------------+------------+ > | | a1ec4288c6 > | 6fe1f1b9b1 | > +---------------------------------------------------------------+------------+------------+ > | boot_successes | 10 > | 71 | > | early-boot-hang | 1 > | | > | boot_failures | 0 > | 9 | > | kernel_BUG_at_kernel/smpboot.c | 0 > | 5 | > | invalid_opcode | 0 > | 5 | > | RIP:smpboot_thread_fn | 0 > | 5 | > | Kernel_panic-not_syncing:Fatal_exception | 0 > | 5 | > | Kernel_panic-not_syncing:Watchdog_detected_hard_LOCKUP_on_cpu | 0 > | 1 | > | backtrace:cpu_up | 0 > | 1 | > | backtrace:smp_init | 0 > | 1 | > | backtrace:kernel_init_freeable | 0 > | 1 | > | BUG:kernel_test_crashed | 0 > | 3 | > +---------------------------------------------------------------+------------+------------+ > > > [ 3.205664] masked ExtINT on CPU#98 > [ 3.205664] CPU98: Thermal LVT vector (0xfa) already installed > [ 3.234545] ------------[ cut here ]------------ > [ 3.235000] kernel BUG at kernel/smpboot.c:134! > [ 3.235000] invalid opcode: 0000 [#1] SMP > [ 3.235000] Modules linked in: > [ 3.235000] CPU: 0 PID: 789 Comm: watchdog/98 Not tainted > 3.17.0-rc7-g6fe1f1b #7 > [ 3.235000] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS > BKLDSDP1.86B.0031.R01.1304221600 04/22/2013 > [ 3.235000] task: ffff881853ed8000 ti: ffff881853ee0000 task.ti: > ffff881853ee0000 > [ 3.235000] RIP: 0010:[<ffffffff810920c0>] [<ffffffff810920c0>] > smpboot_thread_fn+0x180/0x200 > [ 3.235000] RSP: 0000:ffff881853ee3e88 EFLAGS: 00010202 > [ 3.235000] RAX: 0000000000000000 RBX: ffff881853ed8000 RCX: > 0000000000000000 > [ 3.235000] RDX: ffff881853ee3fd8 RSI: ffff881853ed8000 RDI: > 0000000000000062 > [ 3.235000] RBP: ffff881853ee3ec8 R08: ffff881853ee0000 R09: > 0000000000000000 > [ 3.235000] R10: 0000000000000001 R11: 0000000000000001 R12: > ffff88185458e3e0 > [ 3.235000] R13: ffffffff81cc6640 R14: ffff881853ed8000 R15: > ffff881853ed8000 > [ 3.235000] FS: 0000000000000000(0000) GS:ffff88085f800000(0000) > knlGS:0000000000000000 > [ 3.235000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 3.235000] CR2: ffff88207f174000 CR3: 000000207ec38000 CR4: > 00000000001407f0 > [ 3.235000] Stack: > [ 3.235000] 0000000000000000 ffff881853ee3ea0 ffffffff81858ff9 > ffff881853cfbe40 > [ 3.235000] ffff88185458e3e0 ffffffff81091f40 0000000000000000 > 0000000000000000 > [ 3.235000] ffff881853ee3f48 ffffffff8108e1ab 0000000000000001 > 0000000000000062 > [ 3.235000] Call Trace: > [ 3.235000] [<ffffffff81858ff9>] ? schedule+0x29/0x70 > [ 3.235000] [<ffffffff81091f40>] ? SyS_setgroups+0x180/0x180 > [ 3.235000] [<ffffffff8108e1ab>] kthread+0xdb/0x100 > [ 3.235000] [<ffffffff8108e0d0>] ? kthread_create_on_node+0x180/0x180 > [ 3.235000] [<ffffffff8185e97c>] ret_from_fork+0x7c/0xb0 > [ 3.235000] [<ffffffff8108e0d0>] ? kthread_create_on_node+0x180/0x180 > [ 3.235000] Code: 44 00 00 41 8b 3c 24 65 8b 14 25 2c b0 00 00 39 d7 0f 85 > 84 00 00 00 ff d0 41 c7 44 24 04 02 00 00 00 e9 1d ff ff ff 0f 1f 40 00 <0f> > 0b 66 0f 1f 44 00 00 48 c7 45 c8 00 00 00 00 48 8b 45 c8 65 > [ 3.235000] RIP [<ffffffff810920c0>] smpboot_thread_fn+0x180/0x200 > [ 3.235000] RSP <ffff881853ee3e88> > [ 3.235033] ---[ end trace c537e15456e615c3 ]--- > [ 3.236004] Kernel panic - not syncing: Fatal exception > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
