----- Original Message ----- > On Thu, Jun 02, 2011 at 07:31:43AM -0700, Chris Wright wrote: > > * CAI Qian (caiqian@xxxxxxxxxx) wrote: > > > madvise(0x2210000, 4096, 0xc /* MADV_??? */) = 0 > > > --- SIGSEGV (Segmentation fault) @ 0 (0) --- > > > > Right, that's just what the program is trying to do, segfault. > > > > > +++ killed by SIGSEGV (core dumped) +++ > > > Segmentation fault (core dumped) > > > > > > Did I miss anything? > > > > I found it works but not 100% of the time. > > > > So I just run the bug in a loop. > > echo 0 >scan_millisecs helps. Thanks. Indeed. NULL pointer dereference at 0000000000000060 IP: [<ffffffff814d2659>] down_read+0x19/0x30 PGD 0 Oops: 0002 [#1] SMP CPU 0 Modules linked in: autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf ipv6 dm_mirror dm_region_hash dm_log cdc_ether usbnet mii microcode serio_raw pcspkr i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support sg shpchp ioatdma dca i7core_edac edac_core bnx2 ext4 mbcache jbd2 sd_mod crc_t10dif pata_acpi ata_generic ata_piix mptsas mptscsih mptbase scsi_transport_sas dm_mod [last unloaded: scsi_wait_scan] Pid: 103, comm: ksmd Not tainted 3.0.0-rc1+ #6 IBM System x3550 M3 -[7944I21]-/69Y4438 RIP: 0010:[<ffffffff814d2659>] [<ffffffff814d2659>] down_read+0x19/0x30 RSP: 0018:ffff880271307e00 EFLAGS: 00010246 RAX: 0000000000000060 RBX: 0000000000000060 RCX: 00000000000000db RDX: 0000000000000000 RSI: 0000000000000282 RDI: 0000000000000060 RBP: ffff880271307e10 R08: 00000000000000df R09: ffff88026fcff400 R10: 0001b690ffffff90 R11: 0001b690ffffff90 R12: ffff880271307ea8 R13: 0000000000000050 R14: 0000000000000000 R15: ffffffff81a54960 FS: 0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000060 CR3: 0000000001a03000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process ksmd (pid: 103, threadinfo ffff880271306000, task ffff8802712fc0c0) Stack: ffff880271307e10 ffff8802712fc0c0 ffff880271307e60 ffffffff81146e09 ffff8802712fc0c0 0000000000000060 ffff880271307e80 ffff8802712fc0c0 ffff880271307e80 ffff8802712fc0c0 ffff8802712fc0c0 0000000000000063 Call Trace: [<ffffffff81146e09>] scan_get_next_rmap_item+0x59/0x400 [<ffffffff811476ce>] ksm_scan_thread+0xfe/0x2c0 [<ffffffff81084d50>] ? wake_up_bit+0x40/0x40 [<ffffffff811475d0>] ? cmp_and_merge_page+0x420/0x420 [<ffffffff810846d6>] kthread+0x96/0xa0 [<ffffffff814dc544>] kernel_thread_helper+0x4/0x10 [<ffffffff81084640>] ? kthread_worker_fn+0x1a0/0x1a0 [<ffffffff814dc540>] ? gs_change+0x13/0x13 Code: 9e cd d6 ff 48 83 c4 08 5b c9 c3 0f 1f 80 00 00 00 00 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 48 89 fb e8 0a ee ff ff 48 89 d8 <f0> 48 ff 00 79 05 e8 3c cd d6 ff 48 83 c4 08 5b c9 c3 00 00 00 RIP [<ffffffff814d2659>] down_read+0x19/0x30 RSP <ffff880271307e00> CR2: 0000000000000060 ---[ end trace a6feafc139ba5f85 ]--- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>