On Tue, 6 Apr 2021 14:36:19 +0200 Oleksandr Natalenko wrote:
> Hello.
>
> I've raised this here [1] first, but was suggested to engage igb devs,
> so here we are.
>
> I'm experiencing the following woes while using netconsole regularly:
>
> ```
> [22038.710800] ------------[ cut here ]------------
> [22038.710801] igb_poll+0x0/0x1440 [igb] exceeded budget in poll
> [22038.710802] WARNING: CPU: 12 PID: 40362 at net/core/netpoll.c:155
> netpoll_poll_dev+0x18a/0x1a0
> [22038.710802] Modules linked in: ...
> [22038.710835] CPU: 12 PID: 40362 Comm: systemd-sleep Not tainted 5.11.0-pf7
> #1
> [22038.710836] Hardware name: ASUS System Product Name/Pro WS X570-ACE, BIOS
> 3302 03/05/2021
> [22038.710836] RIP: 0010:netpoll_poll_dev+0x18a/0x1a0
> [22038.710837] Code: 6e ff 80 3d d2 9d f8 00 00 0f 85 5c ff ff ff 48 8b 73 28
> 48 c7 c7 0c b8 21 84 89 44 24 04 c6 05 b6 9d f8 00 01 e8 84 21 1c 00 <0f> 0b
> 8b 54 24 04 e9 36 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00
> [22038.710838] RSP: 0018:ffffb24106e37ba0 EFLAGS: 00010086
> [22038.710838] RAX: 0000000000000000 RBX: ffff9599d2929c50 RCX:
> ffff959f8ed1ac30
> [22038.710839] RDX: 0000000000000000 RSI: 0000000000000023 RDI:
> ffff959f8ed1ac28
> [22038.710839] RBP: ffff9598981d4058 R08: 0000000000000019 R09:
> ffffb24206e3796d
> [22038.710839] R10: ffffffffffffffff R11: ffffb24106e37968 R12:
> ffff959887e51ec8
> [22038.710840] R13: 000000000000000c R14: 00000000ffffffff R15:
> ffff9599d2929c60
> [22038.710840] FS: 00007f3ade370a40(0000) GS:ffff959f8ed00000(0000)
> knlGS:0000000000000000
> [22038.710841] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [22038.710841] CR2: 0000000000000000 CR3: 00000003017b0000 CR4:
> 0000000000350ee0
> [22038.710841] Call Trace:
> [22038.710842] netpoll_send_skb+0x185/0x240
> [22038.710842] write_msg+0xe5/0x100 [netconsole]
> [22038.710842] console_unlock+0x37d/0x640
> [22038.710842] ? __schedule+0x2e5/0xc90
> [22038.710843] suspend_devices_and_enter+0x2ac/0x7f0
> [22038.710843] pm_suspend.cold+0x321/0x36c
> [22038.710843] state_store+0xa6/0x140
> [22038.710844] kernfs_fop_write_iter+0x124/0x1b0
> [22038.710844] new_sync_write+0x16a/0x200
> [22038.710844] vfs_write+0x21c/0x2e0
> [22038.710844] __x64_sys_write+0x6d/0xf0
> [22038.710845] do_syscall_64+0x33/0x40
> [22038.710845] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> [22038.710845] RIP: 0033:0x7f3adece10f7
> [22038.710846] Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00
> f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d
> 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
> [22038.710847] RSP: 002b:00007ffc51c555b8 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000001
> [22038.710847] RAX: ffffffffffffffda RBX: 0000000000000004 RCX:
> 00007f3adece10f7
> [22038.710848] RDX: 0000000000000004 RSI: 00007ffc51c556a0 RDI:
> 0000000000000004
> [22038.710848] RBP: 00007ffc51c556a0 R08: 000055ea374302a0 R09:
> 00007f3aded770c0
> [22038.710849] R10: 00007f3aded76fc0 R11: 0000000000000246 R12:
> 0000000000000004
> [22038.710849] R13: 000055ea3742c430 R14: 0000000000000004 R15:
> 00007f3adedb3700
> [22038.710849] ---[ end trace 6eae54fbf23807f8 ]---
> ```
>
> This one happened during suspend/resume cycle (on resume), followed by:
>
> ```
> [22038.868669] igb 0000:05:00.0 enp5s0: Reset adapter
> [22040.998673] igb 0000:05:00.0 enp5s0: Reset adapter
> [22043.819198] igb 0000:05:00.0 enp5s0: igb: enp5s0 NIC Link is Up 1000 Mbps
> Full Duplex, Flow Control: RX
> ```
>
> I've bumped into a similar issue in BZ 211911 [2] (see c#16),
> and in c#17 it was suggested it was a separate unrelated issue,
> hence I'm raising a new concern.
>
> Please help in finding out why this woe happens and in fixing it.
>
> Thanks.
>
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=212573
> [2] https://bugzilla.kernel.org/show_bug.cgi?id=211911
Looks like igb_clean_tx_irq() should not return true if budget is 0,
ever, otherwise we risk hitting the min(work, budget - 1) which may
go negative.
So something like this?
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
b/drivers/net/ethernet/intel/igb/igb_main.c
index c9e8c65a3cfe..7a237b5311ca 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -8028,7 +8028,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector
*q_vector, int napi_budget)
unsigned int i = tx_ring->next_to_clean;
if (test_bit(__IGB_DOWN, &adapter->state))
- return true;
+ goto out;
tx_buffer = &tx_ring->tx_buffer_info[i];
tx_desc = IGB_TX_DESC(tx_ring, i);
@@ -8157,7 +8157,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector
*q_vector, int napi_budget)
tx_ring->queue_index);
/* we are about to reset, no point in enabling stuff */
- return true;
+ goto out;
}
}
@@ -8180,7 +8180,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector
*q_vector, int napi_budget)
u64_stats_update_end(&tx_ring->tx_syncp);
}
}
-
+out:
return !!budget;
}
