Jack clients cannot use real-time scheduling with kernel 5.4.0-25-generic
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
lightdm (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned |
Bug Description
With kernels 5.4.0-24-generic and 5.4.0-25-generic Jack client applications can no longer use real-time scheduling. Kernel 5.4.0-23-generic works.
For example starting guitarix or ardour produces the following logs on stderr:
Cannot use real-time scheduling (RR/5)(1: Operation not permitted)
JackClient:
The following is a strace from an older (working) kernel:
sched_get_
sched_get_
sched_get_
sched_get_
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|
mprotect(
clone(child_
ONE_SYSVSEM|
87c700, child_tidptr=
sched_setschedu
Compare against an strace with an affected kernel:
sched_get_
sched_get_
sched_get_
sched_get_
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|
mprotect(
clone(child_
ONE_SYSVSEM|
fee700, child_tidptr=
sched_setschedu
Apparently a duplicate of https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1873315