Lots and lots of log-spamming. Is there a way to block these log messages? W11 works fine but log messages are a pain.
Dist: Slackware-15
Kernel: 5.16.10
vmmon and vmnet: mkubecek github
VMWare Player: 16.2.1
Windows 11 Pro x64
Early printk:
[ 0.000000] Linux version 5.16.10 (root@tommyv) (gcc (GCC) 11.2.0, GNU ld version 2.37-slack15) #12 SMP PREEMPT Wed Feb 16 16:39:37 CST 2022
[ 0.000000] Command line: BOOT_IMAGE=dev000:EFI\Slackware\vmlinuz root=/dev/NVLVM/root logo.nologo quiet ro
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] x86/split lock detection: #AC: crashing the kernel on kernel split_locks and warning on user-space split_locks
Later:
[59102.255292] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
[59103.256407] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
[59104.257545] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
[59105.258636] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
[59106.259742] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
[59159.314386] x86/split lock detection: #AC: main-mks/30630 took a split_lock trap at address: 0x55987d0a30a7
[59159.314401] x86/split lock detection: #AC: main-svga/30631 took a split_lock trap at address: 0x55987d0a2e3d
and so on.....
If I disable userspace warnings, does this matter? Is there a reason this is occurring?
Thank you
Ref: kernel_parameters.txt
split_lock_detect=
[X86] Enable split lock detection or bus lock detection
When enabled (and if hardware support is present), atomic
instructions that access data across cache line
boundaries will result in an alignment check exception
for split lock detection or a debug exception for
bus lock detection.
off - not enabled
warn - the kernel will emit rate-limited warnings
about applications triggering the #AC
exception or the #DB exception. This mode is
the default on CPUs that support split lock
detection or bus lock detection. Default
behavior is by #AC if both features are
enabled in hardware.
fatal - the kernel will send SIGBUS to applications
that trigger the #AC exception or the #DB
exception. Default behavior is by #AC if
both features are enabled in hardware.
ratelimit:N -
Set system wide rate limit to N bus locks
per second for bus lock detection.
0 < N <= 1000.
N/A for split lock detection.
I added the boot time kernel command line option
split_lock_detect=off
and that has suppressed detection and all messages
[ 0.000000] Linux version 5.16.10 (root@tommyv) (gcc (GCC) 11.2.0, GNU ld version 2.37-slack15) #12 SMP PREEMPT Wed Feb 16 16:39:37 CST 2022
[ 0.000000] Command line: BOOT_IMAGE=dev000:EFI\Slackware\vmlinuz root=/dev/NVLVM/root logo.nologo quiet ro split_lock_detect=off
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] x86/split lock detection: disabled
The important question to be answered is: does this matter? Have any negative impacts? We shall see.
HOST OS: Ubuntu 21.10
Kernel: 5.13.0-52-generic
VMWare: Workstation Pro 16.2.3
Hello,
I was having this problem as well, and it corresponded with when I opened a 3D accelerated application. It was very severe. Namely the vmx-svga module was causing this in VMWare 16.2.3, which would cause a fatal Virtual Machine Kernel Panic, causing the virtual machine to completely crash. I searched around on the forums, and while this forum post didn't mention "split lock", it recommended downgrading to 16.1.
I downgraded, and the same 3D accelerated application that triggered the problem originally everytime has not triggered the issue so far.
Here is my dmesg log:
[60392.347550] split_lock_warn: 15 callbacks suppressed
[60392.347552] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60392.706970] x86/split lock detection: #AC: vmx-svga/539292 took a split_lock trap at address: 0x558591cfebb7
[60392.725529] x86/split lock detection: #AC: vmx-svga/539292 took a split_lock trap at address: 0x558591cfebb7
[60542.767975] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60547.772586] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60561.787282] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60588.812873] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60589.814073] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60652.875259] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60654.876705] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60655.876818] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60657.878961] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60673.894625] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60720.941230] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60721.941778] x86/split lock detection: #AC: main-svga/539295 took a split_lock trap at address: 0x557ff56a2e3d
[60722.941962] x86/split lock detection: #AC: main-mks/539294 took a split_lock trap at address: 0x557ff56a30a7
My suspicion is that all of these split locks then cause the following mks panic:
2022-06-28T01:29:29.219Z In(05) mks SOCKET 2 (5) recv detected client closed connection
2022-06-28T01:29:29.219Z In(05) mks MKSControlMgr: MKSControl Remote Disconnect: socket closed.
2022-06-28T01:29:29.219Z Wa(03) mks MKSResponse: Error: (1084)
2022-06-28T01:29:29.219Z In(05) mks MKSControlMgr: MKSResponse error
2022-06-28T01:29:29.219Z In(05) mks MKSControlMgr: Dropping MKSControl error due to prior unresolved error.
2022-06-28T01:29:29.219Z In(05) mks SOCKET 1 (3) recv error 104: Connection reset by peer
2022-06-28T01:29:29.219Z Wa(03) mks The mksSandbox lost its connection to the main mks.
2022-06-28T01:29:29.219Z Wa(03) mks The main mks process may have crashed or hung.
2022-06-28T01:29:29.219Z Wa(03) mks Check the mksSandbox.log and vmware.log for more details.
2022-06-28T01:29:29.219Z Cr(01) mks PANIC: MKSSandboxComm: Lost connection to isbRenderer (1206)
same issue with Ubuntu 22.04