nvd0 lockup while compiling ports

[Gerhard Schmidt]

Hi,

I've got a new Workstation last week with the Main HD as M2 Card.

FreeBSD recognizes the card as nvd0
nvd0: <Samsung SSD 960 PRO 512GB> NVMe namespace
nvd0: 488386MB (1000215216 512 byte sectors)

When compiling some ports (in this example VirtualBox-ose) I
experiencing lockups on the Harddisk when many files are deleted.

here is the entries gstat reports

dT: 1.064s  w: 1.000s
 L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w   %busy Name
 25281    769      0      0    0.0      0      0    0.0  100.0| nvd0
 25279    769      0      0    0.0      0      0    0.0  100.0| nvd0p4
 25279    769      0      0    0.0      0      0    0.0  100.0| ufs/USR

here the right part of gstat -d -o

dT: 1.003s  w: 1.000s
    d/s   kBps   ms/d    o/s   ms/o   %busy Name
    770  24641  31965      0    0.0  100.1| nvd0
    770  24641  31965      0    0.0  100.1| nvd0p4
    770  24641  31965      0    0.0  100.1| ufs/USR

the numbers under L(q) go up to about 160000 and as long as theses
operations are not finisched, no outer file operation is possible on
this filesystem.

The number of ops/s and d/s is constant aproximatly 770.

Is there a way to speed up delete operations or limit the queue length?

Regards
   Estartu