From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756967AbYLOVMV (ORCPT ); Mon, 15 Dec 2008 16:12:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755849AbYLOVMN (ORCPT ); Mon, 15 Dec 2008 16:12:13 -0500 Received: from static-62-123-141-83.atlanet.it ([62.123.141.83]:54450 "EHLO fourier.campana.vi.it" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755689AbYLOVML (ORCPT ); Mon, 15 Dec 2008 16:12:11 -0500 X-Greylist: delayed 2021 seconds by postgrey-1.27 at vger.kernel.org; Mon, 15 Dec 2008 16:12:09 EST Message-ID: <4946CEF1.6060405@dei.unipd.it> Date: Mon, 15 Dec 2008 21:41:05 +0000 From: Ottavio Campana User-Agent: Mozilla-Thunderbird 2.0.0.17 (X11/20081018) MIME-Version: 1.0 To: Pekka Enberg Cc: linux-kernel@vger.kernel.org Subject: Re: Oops when trying to create more than 16000 timers References: <49468024.1020700@dei.unipd.it> <84144f020812150845g10a1ce26ke2844ab495d2591b@mail.gmail.com> In-Reply-To: <84144f020812150845g10a1ce26ke2844ab495d2591b@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pekka Enberg wrote: > Hi Ottavio, > > On Mon, Dec 15, 2008 at 6:04 PM, Ottavio Campana > 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. PGD 7adfc067 PUD 7ad5e067 PMD 0 CPU 1 Modules linked in: ipv6 dm_snapshot dm_mirror dm_log dm_mod loop e1000 snd_hda_intel snd_pcm_oss snd_pcm snd_mixer_oss snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_timer snd_seq_device parport_pc psmouse iTCO_wdt snd parport i2c_i801 serio_raw soundcore i2c_core pcspkr snd_page_alloc evdev button intel_agp dcdbas ext3 jbd mbcache sg sr_mod cdrom sd_mod ata_piix uhci_hcd ehci_hcd e1000e ide_pci_generic ide_core ata_generic libata scsi_mod dock thermal processor fan thermal_sys Pid: 2743, comm: timer_tester Not tainted 2.6.26-1-amd64 #1 RIP: 0010:[] [] 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: [] vfs_write+0x121/0x156 [] sys_write+0x60/0x6e [] 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 [] sys_timer_create+0x79/0x360 RSP 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