Bug 214809

Summary: devd slows down the full system since upgrade from 10.3 RELEASE
Product: Base System Reporter: Clément BRUGUERA <clebig>
Component: binAssignee: freebsd-bugs (Nobody) <bugs>
Status: New ---    
Severity: Affects Only Me CC: clebig, linimon
Priority: --- Keywords: regression
Version: 11.0-RELEASE   
Hardware: amd64   
OS: Any   
Description Flags
devd -d text output none

Description Clément BRUGUERA 2016-11-24 15:29:19 UTC
Created attachment 177360 [details]
devd -d text output

Dear all,

I'm experiencing a problem with devd since I have upgraded my system from FreeBSD 10.3 RELEASE to FreeBSD 11.0-RELEASE-p3.

The machine is an old Dual-Core AMD Opteron(tm) Processor 1214 Hammer 2.2 Ghz, 4 GB of RAM and a ZFS rootfs.

During the boot, the system becomes extremely slow as soon as init starts devd.

After the boot, killing devd doesn't help, the system is still slow.

When shutdown -r now is entered, the system remain slow until the machine reset.

Tests done :
I deactivated devd in /etc/rc.conf and the system is booting and working normally.

As soon as I start devd manually, the system becomes slow.
If I start devd -d, devd does not end of seg fault, it stays blocked on "Popping table" after an event is detected on ums0 mouse kernel module. 
If devd is interrupted or killed, the system remains slow.

If I boot on kernel.old (from 10.3 RELEASE), the system boots normaly and is working flawlessly.

Booting on the new kernel having deactivated the ums module doesn't change the devd behavior, it is still slowing down the entire system as soon it is started.