Messages in this thread | | | Date | Mon, 15 Dec 2008 23:37:38 +0200 | From | "Pekka Enberg" <> | Subject | Re: Oops when trying to create more than 16000 timers |
| |
Hi Ottavio,
On Mon, Dec 15, 2008 at 11:41 PM, Ottavio Campana <ottavio.campana@dei.unipd.it> wrote: >>> I am currently developing a software that needs approx 60k timers. I >>> currently use timer_create and all the relative functions to manage timers. >>> >>> I've noticed that after having created 16039 timers I always get an oops >>> from the kernel, which are always of the same kind: >>> >>> Dec 15 15:20:00 evolution kernel: [601680.417064] BUG: unable to handle >>> kernel NULL pointer dereference at 0000000000000040 . >> >> This would be a kernel bug so can you please post the full oops. See >> REPORTING-BUGS and Documentation/oops-tracing.txt for details. > > I hope the report is correct, please tell me if you want me to do > something else. > > RIP: 0010:[<ffffffff80245291>] [<ffffffff80245291>] > sys_timer_create+0x79/0x360 > RSP: 0018:ffff81007a5ddef8 EFLAGS: 00010286 > RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000086 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000286 > RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000001 > R10: 00007f927adb3a50 R11: 0000000000000000 R12: 00000000016ed768 > R13: 00000000016ed6d0 R14: 00007fff833dead0 R15: 00000000016ed754 > FS: 00007f927b3cd6e0(0000) GS:ffff81007d37a9c0(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 0000000000000040 CR3: 000000007b00c000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process timer_tester (pid: 2743, threadinfo ffff81007a5dc000, task > ffff81007a7936b0) > Stack: ffff81007646f9f8 0000000000000000 0000000000000000 ffffffff8029b4ed > 0000000000000000 ffff81007b024c80 0000000000000017 fffffffffffffff7 > 00007f927b3da000 ffffffff8029ba36 0000000000000292 0000000000000000 > Call Trace: > [<ffffffff8029b4ed>] vfs_write+0x121/0x156 > [<ffffffff8029ba36>] sys_write+0x60/0x6e > [<ffffffff8020beca>] system_call_after_swapgs+0x8a/0x8f > > > Code: c6 0e 05 00 48 85 c0 74 3b 48 89 c5 e8 d0 a0 ff ff 48 85 c0 48 89 > 45 40 75 11 48 8b 3d e1 22 3e 00 48 89 ee 31 ed e8 fe 10 05 00 <48> 8b > 7d 40 31 f6 ba 80 00 00 00 48 83 c7 18 e8 6b ae 0d 00 48 > RIP [<ffffffff80245291>] sys_timer_create+0x79/0x360 > RSP <ffff81007a5ddef8> > CR2: 0000000000000040 > ---[ end trace 2e93d77cdbbd83c6 ]--- > > Using decodecode > > Code: c6 0e 05 00 48 85 c0 74 3b 48 89 c5 e8 d0 a0 ff ff 48 85 c0 48 89 > 45 40 75 11 48 8b 3d e1 22 3e 00 48 89 ee 31 ed e8 fe 10 05 00 <48> 8b > 7d 40 31 f6 ba 80 00 00 00 48 83 c7 18 e8 6b ae 0d 00 48 > > /tmp/tmp.CcCjFxHOMN.o: file format elf64-x86-64 > > Disassembly of section .text: > > 0000000000000000 <.text>: > 0: c6 (bad) > 1: 0e (bad) > 2: 05 00 48 85 c0 add $0xc0854800,%eax > 7: 74 3b je 0x44 > 9: 48 89 c5 mov %rax,%rbp > c: e8 d0 a0 ff ff callq 0xffffffffffffa0e1 > 11: 48 85 c0 test %rax,%rax > 14: 48 89 45 40 mov %rax,0x40(%rbp) > 18: 75 11 jne 0x2b > 1a: 48 8b 3d e1 22 3e 00 mov 0x3e22e1(%rip),%rdi # 0x3e2302 > 21: 48 89 ee mov %rbp,%rsi > 24: 31 ed xor %ebp,%ebp > 26: e8 fe 10 05 00 callq 0x51129 > > /tmp/tmp.CcCjFxHOMN.o: file format elf64-x86-64 > > Disassembly of section .text: > > 0000000000000000 <.text>: > 0: 48 8b 7d 40 mov 0x40(%rbp),%rdi > 4: 31 f6 xor %esi,%esi > 6: ba 80 00 00 00 mov $0x80,%edx > b: 48 83 c7 18 add $0x18,%rdi > f: e8 6b ae 0d 00 callq 0xdae7f > 14: 48 rex.W
I think you're simply hitting RLIMIT_SIGPENDING and then tripping over a bug in alloc_posix_timer() that's fixed by commit aa94fbd5ccd840c8ab26d02439ec799b03a72547 ("fix error-path NULL deref in alloc_posix_timer()") in 2.6.28-rc8.
Dan, can you please send your patch to the -stable queue as well?
Pekka
| |