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New: GRO:__napi_complete from net_rx_action crash

Bugme-new Applied Andrew Morton 4 participants 6 messages Jun 25, 2009 – Jun 27, 2009 1 message not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]/

#1 lore raw

(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface).

netdev core crashed. The netxen driver may be implicated.

Why did [email protected] create this bug report? Isn't Dhananjay sitting in the next cube? Perhaps you believe that the driver is OK and that the bug lies in the netdev core?

Quoted 134 lines · On Thu, 25 Jun 2009 06:55:14 GMT [email protected] wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=13617

Summary: GRO:__napi_complete from net_rx_action crash
Product: Drivers
Version: 2.5
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: Network
AssignedTo: [email protected]
ReportedBy: [email protected]
Regression: No

In net_rx_action, there is check if napi_disable_pending then call __napi_complete.
In __napi_complete, there is BUG_ON(n->gro_list);
Which has hit in below bug dump.
Why __napi_complete is called from net_rx_action instead of napi_complete. napi_complete flushes the gro list.

Below code excerpt from net_rx_action
http://lxr.linux.no/linux+v2.6.30/net/core/dev.c#L2736

   if (unlikely(work == weight)) {

2791 if (unlikely(napi_disable_pending(n)))
2792 __napi_complete(n);
2793 else
2794 list_move_tail(&n->poll_list, list);
2795 }

------------[ cut here ]------------
kernel BUG at net/core/dev.c:2672!
invalid opcode: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 2 
Modules linked in: netxen_nic nfs lockd nfs_acl auth_rpcgss ipv6 deflate

zlib_deflate ctr twofish twofish_common serpent blowfish des_generic cbc aes_x86_64 aes_generic xcbc sha256_generic md5 crypto_null af_key autofs4 sunrpc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi dm_mirror dm_region_hash dm_log dm_multipath dm_mod video output sbs sbshc pci_slot battery acpi_memhotplug ac parport ipmi_devintf ide_cd_mod rtc_cmos bnx2 cdrom serio_raw ipmi_si rtc_core button ipmi_msghandler iTCO_wdt rtc_lib shpchp hpilo hpwdt i5000_edac pcspkr edac_core ata_piix libata sd_mod scsi_mod cciss ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
Pid: 0, comm: swapper Tainted: G W 2.6.30 #1 ProLiant DL380 G5

RIP: 0010:[<ffffffff8043b128>]  [<ffffffff8043b128>] __napi_complete+0x15/0x25
RSP: 0018:ffff880028139eb0  EFLAGS: 00010086
RAX: ffff88023d4056b8 RBX: ffff88023d4056a8 RCX: 0000000002202318
RDX: 00000000001b0000 RSI: ffff880028139d98 RDI: ffff88023d4056a8
RBP: 0000000000000080 R08: 0000000002200000 R09: 000006de15931680
R10: ffffc20011a32318 R11: 0000000000000005 R12: 0000000000000000
R13: ffff8800281440e0 R14: 0000000000000080 R15: 000000000000012c
FS:  0000000000000000(0000) GS:ffff880028136000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 00000000008cb530 CR3: 000000023d9ab000 CR4: 00000000000006e0
Jun 23 23:41:27 DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffff88023ed28000, task ffff88023ed27570)
Stack:
 ffff88023d4056a8 ffffffff8043ec9f 0000000000000001dut4146 last mes

000000010004f429
ffff88023d4056b8sage repeated 6 0000000000000046 0000000000000001
0000000000000100times
Jun 23 23
ffffffff8069a098 0000000000000018 000000000000000a:41:32 dut4146 k
ffffffff8023eba6
ernel: BUG: scheCall Trace:
duling while ato <IRQ> <0>mic: swapper/0/0 [<ffffffff8043ec9f>] ?

net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28

x10000100
Jun 2 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
[<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
3 23:41:32 dut41 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
<EOI> 46 kernel: Modul<0> [<ffffffff80220e41>] ?

hpet_legacy_next_event+0x0/0x7
es linked in: ne [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
Code: txen_nic nfs loc48 8d kd nfs_acl auth_43 70 48 rpcgss ipv6 defl39 c2 ate

zlib_deflate0f ctr twofish two18 0e 75 fish_common serpdf ent blowfish des31 c9 41 _generic cbc aes58 5b _x86_64 aes_gene5d 48 89 ric xcbc sha256_c8 c3 generic md5 cryp53 f6 to_null af_key a47 10 01 utofs4 sunrpc is48 89 fb csi_tcp libiscsi75 04 _tcp libiscsi sc0f 0b eb si_transport_iscfe 48 83 si dm_mirror dm_7f 50 region_hash dm_l00 74 04 og dm_multipath <0f> dm_mod video out0b eb put sbs sbshc pcfe e8 i_slot battery a1f cpi_memhotplug a10 f1 ff c parport ipmi_df0 80 evintf ide_cd_mo63 10 fe d rtc_cmos bnx2 5b c3 cdrom serio_raw 53 48 89 ipmi_si rtc_corefb e8
button ipmi_msgRIP [<ffffffff8043b128>] __napi_complete+0x15/0x25 RSP <ffff880028139eb0>

---[ end trace 9c6b22b26aefd1b1 ]---
handler iTCO_wdtKernel panic - not syncing: Fatal exception in interrupt
Pid: 0, comm: swapper Tainted: G      D W  2.6.30 #1
Call Trace:
 <IRQ>  [<ffffffff8023a3b5>] ? panic+0x86/0x134
 [<ffffffff8020e348>] ? show_registers+0x211/0x21d
 [<ffffffff8024f5ea>] ? up+0xe/0x36
 [<ffffffff8023a9db>] ? release_console_sem+0x174/0x18e
 [<ffffffff804bdd54>] ? oops_end+0xa0/0xad
 [<ffffffff8020cf2c>] ? do_invalid_op+0x85/0x8f
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffffa03ebfe2>] ? netxen_nic_hw_write_wx_2M+0x24/0xa8 [netxen_nic]
 [<ffffffffa03ef866>] ? netxen_process_rcv_ring+0x4eb/0x501 [netxen_nic]
 rtc_lib shpchp  [<ffffffff8020c715>] ? invalid_op+0x15/0x20
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffff8043ec9f>] ? net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28
 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
 [<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c
 [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff80220e41>] ? hpet_legacy_next_event+0x0/0x7
 [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
Signature · 3 lines
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#2 lore raw

mea culpa, likely driver can wait more for rx to drain so that we race with napi disable.

Although, I have question for Dave. If napi code is anyway forcing napi completion, should it not flush gro flows also? This code predates GRO.

-Dhananjay

Quoted 154 lines · Andrew Morton

(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface).

netdev core crashed. The netxen driver may be implicated.

Why did [email protected] create this bug report? Isn't Dhananjay sitting in the next cube? Perhaps you believe that the driver is OK and that the bug lies in the netdev core?

Quoted 121 lines · On Thu, 25 Jun 2009 06:55:14 GMT [email protected] wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=13617

Summary: GRO:__napi_complete from net_rx_action crash
Product: Drivers
Version: 2.5
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: Network
AssignedTo: [email protected]
ReportedBy: [email protected]
Regression: No

In net_rx_action, there is check if napi_disable_pending then call __napi_complete.
In __napi_complete, there is BUG_ON(n->gro_list);
Which has hit in below bug dump.
Why __napi_complete is called from net_rx_action instead of napi_complete. napi_complete flushes the gro list.

Below code excerpt from net_rx_action
http://lxr.linux.no/linux+v2.6.30/net/core/dev.c#L2736

   if (unlikely(work == weight)) {

2791 if (unlikely(napi_disable_pending(n)))
2792 __napi_complete(n);
2793 else
2794 list_move_tail(&n->poll_list, list);
2795 }

------------[ cut here ]------------
kernel BUG at net/core/dev.c:2672!
invalid opcode: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 2 
Modules linked in: netxen_nic nfs lockd nfs_acl auth_rpcgss ipv6 deflate

zlib_deflate ctr twofish twofish_common serpent blowfish des_generic cbc aes_x86_64 aes_generic xcbc sha256_generic md5 crypto_null af_key autofs4 sunrpc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi dm_mirror dm_region_hash dm_log dm_multipath dm_mod video output sbs sbshc pci_slot battery acpi_memhotplug ac parport ipmi_devintf ide_cd_mod rtc_cmos bnx2 cdrom serio_raw ipmi_si rtc_core button ipmi_msghandler iTCO_wdt rtc_lib shpchp hpilo hpwdt i5000_edac pcspkr edac_core ata_piix libata sd_mod scsi_mod cciss ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
Pid: 0, comm: swapper Tainted: G W 2.6.30 #1 ProLiant DL380 G5

RIP: 0010:[<ffffffff8043b128>]  [<ffffffff8043b128>] __napi_complete+0x15/0x25
RSP: 0018:ffff880028139eb0  EFLAGS: 00010086
RAX: ffff88023d4056b8 RBX: ffff88023d4056a8 RCX: 0000000002202318
RDX: 00000000001b0000 RSI: ffff880028139d98 RDI: ffff88023d4056a8
RBP: 0000000000000080 R08: 0000000002200000 R09: 000006de15931680
R10: ffffc20011a32318 R11: 0000000000000005 R12: 0000000000000000
R13: ffff8800281440e0 R14: 0000000000000080 R15: 000000000000012c
FS:  0000000000000000(0000) GS:ffff880028136000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 00000000008cb530 CR3: 000000023d9ab000 CR4: 00000000000006e0
Jun 23 23:41:27 DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffff88023ed28000, task ffff88023ed27570)
Stack:
 ffff88023d4056a8 ffffffff8043ec9f 0000000000000001dut4146 last mes

000000010004f429
ffff88023d4056b8sage repeated 6 0000000000000046 0000000000000001
0000000000000100times
Jun 23 23
ffffffff8069a098 0000000000000018 000000000000000a:41:32 dut4146 k
ffffffff8023eba6
ernel: BUG: scheCall Trace:
duling while ato <IRQ> <0>mic: swapper/0/0 [<ffffffff8043ec9f>] ?

net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28

x10000100
Jun 2 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
[<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
3 23:41:32 dut41 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
<EOI> 46 kernel: Modul<0> [<ffffffff80220e41>] ?

hpet_legacy_next_event+0x0/0x7
es linked in: ne [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
Code: txen_nic nfs loc48 8d kd nfs_acl auth_43 70 48 rpcgss ipv6 defl39 c2 ate

zlib_deflate0f ctr twofish two18 0e 75 fish_common serpdf ent blowfish des31 c9 41 _generic cbc aes58 5b _x86_64 aes_gene5d 48 89 ric xcbc sha256_c8 c3 generic md5 cryp53 f6 to_null af_key a47 10 01 utofs4 sunrpc is48 89 fb csi_tcp libiscsi75 04 _tcp libiscsi sc0f 0b eb si_transport_iscfe 48 83 si dm_mirror dm_7f 50 region_hash dm_l00 74 04 og dm_multipath <0f> dm_mod video out0b eb put sbs sbshc pcfe e8 i_slot battery a1f cpi_memhotplug a10 f1 ff c parport ipmi_df0 80 evintf ide_cd_mo63 10 fe d rtc_cmos bnx2 5b c3 cdrom serio_raw 53 48 89 ipmi_si rtc_corefb e8
button ipmi_msgRIP [<ffffffff8043b128>] __napi_complete+0x15/0x25 RSP <ffff880028139eb0>

---[ end trace 9c6b22b26aefd1b1 ]---
handler iTCO_wdtKernel panic - not syncing: Fatal exception in interrupt
Pid: 0, comm: swapper Tainted: G      D W  2.6.30 #1
Call Trace:
 <IRQ>  [<ffffffff8023a3b5>] ? panic+0x86/0x134
 [<ffffffff8020e348>] ? show_registers+0x211/0x21d
 [<ffffffff8024f5ea>] ? up+0xe/0x36
 [<ffffffff8023a9db>] ? release_console_sem+0x174/0x18e
 [<ffffffff804bdd54>] ? oops_end+0xa0/0xad
 [<ffffffff8020cf2c>] ? do_invalid_op+0x85/0x8f
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffffa03ebfe2>] ? netxen_nic_hw_write_wx_2M+0x24/0xa8 [netxen_nic]
 [<ffffffffa03ef866>] ? netxen_process_rcv_ring+0x4eb/0x501 [netxen_nic]
 rtc_lib shpchp  [<ffffffff8020c715>] ? invalid_op+0x15/0x20
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffff8043ec9f>] ? net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28
 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
 [<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c
 [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
Quoted 13 lines
 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff80220e41>] ? hpet_legacy_next_event+0x0/0x7
 [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
Signature · 3 lines
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

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maintainer
#3 lore raw

From: Dhananjay Phadke <[email protected]>
Date: Fri, 26 Jun 2009 10:13:59 -0700

Quoted 6 lines

mea culpa, likely driver can wait more for rx to drain so that we race with napi disable.

Although, I have question for Dave. If napi code is anyway forcing napi completion, should it not flush gro flows also? This code predates GRO.

I think there are some reasons, but Herbert Xu is more likely to remember than I am, CC:'d :-)

Quoted 155 lines
Quoted 154 lines · Andrew Morton

(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface).

netdev core crashed. The netxen driver may be implicated.

Why did [email protected] create this bug report? Isn't Dhananjay sitting in the next cube? Perhaps you believe that the driver is OK and that the bug lies in the netdev core?

Quoted 121 lines · On Thu, 25 Jun 2009 06:55:14 GMT [email protected] wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=13617

Summary: GRO:__napi_complete from net_rx_action crash
Product: Drivers
Version: 2.5
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: Network
AssignedTo: [email protected]
ReportedBy: [email protected]
Regression: No

In net_rx_action, there is check if napi_disable_pending then call __napi_complete.
In __napi_complete, there is BUG_ON(n->gro_list);
Which has hit in below bug dump.
Why __napi_complete is called from net_rx_action instead of napi_complete. napi_complete flushes the gro list.

Below code excerpt from net_rx_action
http://lxr.linux.no/linux+v2.6.30/net/core/dev.c#L2736

   if (unlikely(work == weight)) {

2791 if (unlikely(napi_disable_pending(n)))
2792 __napi_complete(n);
2793 else
2794 list_move_tail(&n->poll_list, list);
2795 }

------------[ cut here ]------------
kernel BUG at net/core/dev.c:2672!
invalid opcode: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 2 
Modules linked in: netxen_nic nfs lockd nfs_acl auth_rpcgss ipv6 deflate

zlib_deflate ctr twofish twofish_common serpent blowfish des_generic cbc aes_x86_64 aes_generic xcbc sha256_generic md5 crypto_null af_key autofs4 sunrpc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi dm_mirror dm_region_hash dm_log dm_multipath dm_mod video output sbs sbshc pci_slot battery acpi_memhotplug ac parport ipmi_devintf ide_cd_mod rtc_cmos bnx2 cdrom serio_raw ipmi_si rtc_core button ipmi_msghandler iTCO_wdt rtc_lib shpchp hpilo hpwdt i5000_edac pcspkr edac_core ata_piix libata sd_mod scsi_mod cciss ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
Pid: 0, comm: swapper Tainted: G W 2.6.30 #1 ProLiant DL380 G5

RIP: 0010:[<ffffffff8043b128>]  [<ffffffff8043b128>] __napi_complete+0x15/0x25
RSP: 0018:ffff880028139eb0  EFLAGS: 00010086
RAX: ffff88023d4056b8 RBX: ffff88023d4056a8 RCX: 0000000002202318
RDX: 00000000001b0000 RSI: ffff880028139d98 RDI: ffff88023d4056a8
RBP: 0000000000000080 R08: 0000000002200000 R09: 000006de15931680
R10: ffffc20011a32318 R11: 0000000000000005 R12: 0000000000000000
R13: ffff8800281440e0 R14: 0000000000000080 R15: 000000000000012c
FS:  0000000000000000(0000) GS:ffff880028136000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 00000000008cb530 CR3: 000000023d9ab000 CR4: 00000000000006e0
Jun 23 23:41:27 DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffff88023ed28000, task ffff88023ed27570)
Stack:
 ffff88023d4056a8 ffffffff8043ec9f 0000000000000001dut4146 last mes

000000010004f429
ffff88023d4056b8sage repeated 6 0000000000000046 0000000000000001
0000000000000100times
Jun 23 23
ffffffff8069a098 0000000000000018 000000000000000a:41:32 dut4146 k
ffffffff8023eba6
ernel: BUG: scheCall Trace:
duling while ato <IRQ> <0>mic: swapper/0/0 [<ffffffff8043ec9f>] ?

net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28

x10000100
Jun 2 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
[<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
3 23:41:32 dut41 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
<EOI> 46 kernel: Modul<0> [<ffffffff80220e41>] ?

hpet_legacy_next_event+0x0/0x7
es linked in: ne [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
Code: txen_nic nfs loc48 8d kd nfs_acl auth_43 70 48 rpcgss ipv6 defl39 c2 ate

zlib_deflate0f ctr twofish two18 0e 75 fish_common serpdf ent blowfish des31 c9 41 _generic cbc aes58 5b _x86_64 aes_gene5d 48 89 ric xcbc sha256_c8 c3 generic md5 cryp53 f6 to_null af_key a47 10 01 utofs4 sunrpc is48 89 fb csi_tcp libiscsi75 04 _tcp libiscsi sc0f 0b eb si_transport_iscfe 48 83 si dm_mirror dm_7f 50 region_hash dm_l00 74 04 og dm_multipath <0f> dm_mod video out0b eb put sbs sbshc pcfe e8 i_slot battery a1f cpi_memhotplug a10 f1 ff c parport ipmi_df0 80 evintf ide_cd_mo63 10 fe d rtc_cmos bnx2 5b c3 cdrom serio_raw 53 48 89 ipmi_si rtc_corefb e8
button ipmi_msgRIP [<ffffffff8043b128>] __napi_complete+0x15/0x25 RSP <ffff880028139eb0>

---[ end trace 9c6b22b26aefd1b1 ]---
handler iTCO_wdtKernel panic - not syncing: Fatal exception in interrupt
Pid: 0, comm: swapper Tainted: G      D W  2.6.30 #1
Call Trace:
 <IRQ>  [<ffffffff8023a3b5>] ? panic+0x86/0x134
 [<ffffffff8020e348>] ? show_registers+0x211/0x21d
 [<ffffffff8024f5ea>] ? up+0xe/0x36
 [<ffffffff8023a9db>] ? release_console_sem+0x174/0x18e
 [<ffffffff804bdd54>] ? oops_end+0xa0/0xad
 [<ffffffff8020cf2c>] ? do_invalid_op+0x85/0x8f
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffffa03ebfe2>] ? netxen_nic_hw_write_wx_2M+0x24/0xa8 [netxen_nic]
 [<ffffffffa03ef866>] ? netxen_process_rcv_ring+0x4eb/0x501 [netxen_nic]
 rtc_lib shpchp  [<ffffffff8020c715>] ? invalid_op+0x15/0x20
 [<ffffffff8043b128>] ? __napi_complete+0x15/0x25
 [<ffffffff8043ec9f>] ? net_rx_action+0xf0/0x162
 [<ffffffff8023eba6>] ? __do_softirq+0xa3/0x163
 [<ffffffff8020ca7c>] ? call_softirq+0x1c/0x28
 [<ffffffff8020dc1a>] ? do_softirq+0x2c/0x68
 [<ffffffff8023eac6>] ? irq_exit+0x3f/0x7c
 [<ffffffff8020d46b>] ? do_IRQ+0xa9/0xbf
Quoted 13 lines
 [<ffffffff8020c353>] ? ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff80220e41>] ? hpet_legacy_next_event+0x0/0x7
 [<ffffffff80386e2c>] ? acpi_hw_register_read+0x52/0xe5
 [<ffffffff80394b2a>] ? acpi_idle_enter_simple+0x120/0x14e
 [<ffffffff80394b20>] ? acpi_idle_enter_simple+0x116/0x14e
 [<ffffffff8039486b>] ? acpi_idle_enter_bm+0xd5/0x274
 [<ffffffff8041c020>] ? cpuidle_idle_call+0x7f/0xbb
 [<ffffffff8020aaa5>] ? cpu_idle+0x4a/0x6d
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#4 lore raw
Quoted 7 lines · David Miller
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines

In net_rx_action, there is check if napi_disable_pending then call __napi_complete.
In __napi_complete, there is BUG_ON(n->gro_list);
Which has hit in below bug dump.
Why __napi_complete is called from net_rx_action instead of napi_complete. napi_complete flushes the gro list.

Indeed, it was an oversight. Thanks for catching it!

gro: Flush GRO packets in napi_disable_pending path

When NAPI is disabled while we're in net_rx_action, we end up calling __napi_complete without flushing GRO packets. This is a bug as it would cause the GRO packets to linger, of course it also literally BUGs to catch error like this :)

This patch changes it to napi_complete, with the obligatory IRQ reenabling. This should be safe because we've only just disabled IRQs and it does not materially affect the test conditions in between.

net/core/dev.c +5 -3
index 60b5728..70c27e0 100644
@@ -2823,9 +2823,11 @@ static void net_rx_action(struct softirq_action *h)
 		 * move the instance around on the list at-will.
 		 */
 		if (unlikely(work == weight)) {
-			if (unlikely(napi_disable_pending(n)))
-				__napi_complete(n);
-			else
+			if (unlikely(napi_disable_pending(n))) {
+				local_irq_enable();
+				napi_complete(n);
+				local_irq_disable();
+			} else
 				list_move_tail(&n->poll_list, list);
 		}
 

Cheers,

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Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
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maintainer Applied
#5 lore raw

From: Herbert Xu <[email protected]>
Date: Sat, 27 Jun 2009 09:49:00 +0800

Quoted 18 lines · David Miller
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines

In net_rx_action, there is check if napi_disable_pending then call __napi_complete.
In __napi_complete, there is BUG_ON(n->gro_list);
Which has hit in below bug dump.
Why __napi_complete is called from net_rx_action instead of napi_complete. napi_complete flushes the gro list.

Indeed, it was an oversight. Thanks for catching it!

gro: Flush GRO packets in napi_disable_pending path

When NAPI is disabled while we're in net_rx_action, we end up calling __napi_complete without flushing GRO packets. This is a bug as it would cause the GRO packets to linger, of course it also literally BUGs to catch error like this :)

Quoted 6 lines

This patch changes it to napi_complete, with the obligatory IRQ reenabling. This should be safe because we've only just disabled IRQs and it does not materially affect the test conditions in between.

Applied.

I remembered that change where we had to disable GRO in the legacy RX path and all the IRQ disabling problems we ran into there. So I went and had a look at that to make sure we won't have similar issues here, luckily it seems not.

Thanks!

#6 lore raw
Quoted 5 lines · David Miller

I remembered that change where we had to disable GRO in the legacy RX path and all the IRQ disabling problems we ran into there. So I went and had a look at that to make sure we won't have similar issues here, luckily it seems not.

Yeah the netpoll lock is all we need since netpoll is the only other thing that can race against this.

Thanks,

Signature · 4 lines
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt