在 2024/1/22 上午11:08, Jason Wang 写道:
On Fri, Jan 19, 2024 at 10:27 PM Heng Qi <hen...@linux.alibaba.com> wrote:
在 2024/1/18 下午8:01, Zhu Yanjun 写道:
在 2024/1/16 20:04, Paolo Abeni 写道:
On Mon, 2024-01-15 at 09:29 +0800, Zhu Yanjun wrote:
From: Zhu Yanjun <yanjun....@linux.dev>
Some devices emulate the virtio_net hardwares. When virtio_net
driver sends commands to the emulated hardware, normally the
hardware needs time to response. Sometimes the time is very
long. Thus, the following will appear. Then the whole system
will hang.
The similar problems also occur in Intel NICs and Mellanox NICs.
As such, the similar solution is borrowed from them. A timeout
value is added and the timeout value as large as possible is set
to ensure that the driver gets the maximum possible response from
the hardware.
"
[ 213.795860] watchdog: BUG: soft lockup - CPU#108 stuck for 26s!
[(udev-worker):3157]
[ 213.796114] Modules linked in: virtio_net(+) net_failover
failover qrtr rfkill sunrpc intel_rapl_msr intel_rapl_common
intel_uncore_frequency intel_uncore_frequency_common intel_ifs
i10nm_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp
coretemp iTCO_wdt rapl intel_pmc_bxt dax_hmem iTCO_vendor_support
vfat cxl_acpi intel_cstate pmt_telemetry pmt_class intel_sdsi joydev
intel_uncore cxl_core fat pcspkr mei_me isst_if_mbox_pci
isst_if_mmio idxd i2c_i801 isst_if_common mei intel_vsec idxd_bus
i2c_smbus i2c_ismt ipmi_ssif acpi_ipmi ipmi_si ipmi_devintf
ipmi_msghandler acpi_pad acpi_power_meter pfr_telemetry pfr_update
fuse loop zram xfs crct10dif_pclmul crc32_pclmul crc32c_intel
polyval_clmulni polyval_generic ghash_clmulni_intel sha512_ssse3
bnxt_en sha256_ssse3 sha1_ssse3 nvme ast nvme_core i2c_algo_bit wmi
pinctrl_emmitsburg scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_multipath
[ 213.796194] irq event stamp: 67740
[ 213.796195] hardirqs last enabled at (67739):
[<ffffffff8c2015ca>] asm_sysvec_apic_timer_interrupt+0x1a/0x20
[ 213.796203] hardirqs last disabled at (67740):
[<ffffffff8c14108e>] sysvec_apic_timer_interrupt+0xe/0x90
[ 213.796208] softirqs last enabled at (67686):
[<ffffffff8b12115e>] __irq_exit_rcu+0xbe/0xe0
[ 213.796214] softirqs last disabled at (67681):
[<ffffffff8b12115e>] __irq_exit_rcu+0xbe/0xe0
[ 213.796217] CPU: 108 PID: 3157 Comm: (udev-worker) Kdump: loaded
Not tainted 6.7.0+ #9
[ 213.796220] Hardware name: Intel Corporation
M50FCP2SBSTD/M50FCP2SBSTD, BIOS SE5C741.86B.01.01.0001.2211140926
11/14/2022
[ 213.796221] RIP: 0010:virtqueue_get_buf_ctx_split+0x8d/0x110
[ 213.796228] Code: 89 df e8 26 fe ff ff 0f b7 43 50 83 c0 01 66 89
43 50 f6 43 78 01 75 12 80 7b 42 00 48 8b 4b 68 8b 53 58 74 0f 66 87
44 51 04 <48> 89 e8 5b 5d c3 cc cc cc cc 66 89 44 51 04 0f ae f0 48
89 e8 5b
[ 213.796230] RSP: 0018:ff4bbb362306f9b0 EFLAGS: 00000246
[ 213.796233] RAX: 0000000000000000 RBX: ff2f15095896f000 RCX:
0000000000000001
[ 213.796235] RDX: 0000000000000000 RSI: ff4bbb362306f9cc RDI:
ff2f15095896f000
[ 213.796236] RBP: 0000000000000000 R08: 0000000000000000 R09:
0000000000000000
[ 213.796237] R10: 0000000000000003 R11: ff2f15095893cc40 R12:
0000000000000002
[ 213.796239] R13: 0000000000000004 R14: 0000000000000000 R15:
ff2f1509534f3000
[ 213.796240] FS: 00007f775847d0c0(0000) GS:ff2f1528bac00000(0000)
knlGS:0000000000000000
[ 213.796242] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 213.796243] CR2: 0000557f987b6e70 CR3: 0000002098602006 CR4:
0000000000f71ef0
[ 213.796245] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 213.796246] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7:
0000000000000400
[ 213.796247] PKRU: 55555554
[ 213.796249] Call Trace:
[ 213.796250] <IRQ>
[ 213.796252] ? watchdog_timer_fn+0x1c0/0x220
[ 213.796258] ? __pfx_watchdog_timer_fn+0x10/0x10
[ 213.796261] ? __hrtimer_run_queues+0x1af/0x380
[ 213.796269] ? hrtimer_interrupt+0xf8/0x230
[ 213.796274] ? __sysvec_apic_timer_interrupt+0x64/0x1a0
[ 213.796279] ? sysvec_apic_timer_interrupt+0x6d/0x90
[ 213.796282] </IRQ>
[ 213.796284] <TASK>
[ 213.796285] ? asm_sysvec_apic_timer_interrupt+0x1a/0x20
[ 213.796293] ? virtqueue_get_buf_ctx_split+0x8d/0x110
[ 213.796297] virtnet_send_command+0x18a/0x1f0 [virtio_net]
[ 213.796310] _virtnet_set_queues+0xc6/0x120 [virtio_net]
[ 213.796319] virtnet_probe+0xa06/0xd50 [virtio_net]
[ 213.796328] virtio_dev_probe+0x195/0x230
[ 213.796333] really_probe+0x19f/0x400
[ 213.796338] ? __pfx___driver_attach+0x10/0x10
[ 213.796340] __driver_probe_device+0x78/0x160
[ 213.796343] driver_probe_device+0x1f/0x90
[ 213.796346] __driver_attach+0xd6/0x1d0
[ 213.796349] bus_for_each_dev+0x8c/0xe0
[ 213.796355] bus_add_driver+0x119/0x220
[ 213.796359] driver_register+0x59/0x100
[ 213.796362] ? __pfx_virtio_net_driver_init+0x10/0x10 [virtio_net]
[ 213.796369] virtio_net_driver_init+0x8e/0xff0 [virtio_net]
[ 213.796375] do_one_initcall+0x6f/0x380
[ 213.796384] do_init_module+0x60/0x240
[ 213.796388] init_module_from_file+0x86/0xc0
[ 213.796396] idempotent_init_module+0x129/0x2c0
[ 213.796406] __x64_sys_finit_module+0x5e/0xb0
[ 213.796409] do_syscall_64+0x60/0xe0
[ 213.796415] ? do_syscall_64+0x6f/0xe0
[ 213.796418] ? lockdep_hardirqs_on_prepare+0xe4/0x1a0
[ 213.796424] ? do_syscall_64+0x6f/0xe0
[ 213.796427] ? do_syscall_64+0x6f/0xe0
[ 213.796431] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 213.796435] RIP: 0033:0x7f7758f279cd
[ 213.796465] Code: 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e
fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24
08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 33 e4 0c 00 f7 d8 64
89 01 48
[ 213.796467] RSP: 002b:00007ffe2cad8738 EFLAGS: 00000246 ORIG_RAX:
0000000000000139
[ 213.796469] RAX: ffffffffffffffda RBX: 0000557f987a8180 RCX:
00007f7758f279cd
[ 213.796471] RDX: 0000000000000000 RSI: 00007f77593e5453 RDI:
000000000000000f
[ 213.796472] RBP: 00007f77593e5453 R08: 0000000000000000 R09:
00007ffe2cad8860
[ 213.796473] R10: 000000000000000f R11: 0000000000000246 R12:
0000000000020000
[ 213.796475] R13: 0000557f9879f8e0 R14: 0000000000000000 R15:
0000557f98783aa0
[ 213.796482] </TASK>
"
Signed-off-by: Zhu Yanjun <yanjun....@linux.dev>
---
drivers/net/virtio_net.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 51b1868d2f22..28b7dd917a43 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2468,7 +2468,7 @@ static bool virtnet_send_command(struct
virtnet_info *vi, u8 class, u8 cmd,
{
struct scatterlist *sgs[4], hdr, stat;
unsigned out_num = 0, tmp;
- int ret;
+ int ret, timeout = 200;
/* Caller should know better */
BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
@@ -2502,8 +2502,14 @@ static bool virtnet_send_command(struct
virtnet_info *vi, u8 class, u8 cmd,
* into the hypervisor, so the request should be handled
immediately.
*/
while (!virtqueue_get_buf(vi->cvq, &tmp) &&
- !virtqueue_is_broken(vi->cvq))
+ !virtqueue_is_broken(vi->cvq)) {
+ if (timeout)
+ timeout--;
This is not really a timeout, just a loop counter. 200 iterations could
be a very short time on reasonable H/W. I guess this avoid the soft
lockup, but possibly (likely?) breaks the functionality when we need to
loop for some non negligible time.
I fear we need a more complex solution, as mentioned by Micheal in the
thread you quoted.
Got it. I also look forward to the more complex solution to this problem.
Can we add a device capability (new feature bit) such as
ctrq_wait_timeout to get a reasonable timeout？
This adds another kind of complexity for migration compatibility.
Yes, this requires device adaptation. But the value will be more
reasonable, different devices have different requirements for timeout.
And we need to make it more general, e.g
1) it should not be cvq specific
Agree. Especially considering avq also has this problem.
2) or we can have a timeout that works for all queues
I remember Parav mentioned that they were also making some bulk
improvements to ctrlq/avq,
or we should look at a combined solution.
rxq timeout can be used for our detection aliveness needs, especially
after a live migration.
txq timeout can be used with watchdog + vq reset.
Thanks,
Heng
?
Thanks
Thanks,
Heng
Zhu Yanjun
Cheers,
Paolo
