lkml.org 
[lkml]   [2018]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [BUG v4.14-rt] kernel BUG at /work/rt/stable-rt.git/kernel/sched/core.c:1639!
    On Sun, 19 Aug 2018 08:28:35 +0200
    Mike Galbraith <efault@gmx.de> wrote:

    > On Sat, 2018-08-18 at 15:13 +0200, Mike Galbraith wrote:
    > > seems it has be something from the 4.17 cycle that went back to 4.14-
    > > stable after 4.1[56]-stable trees went extinct.
    >
    > See ("sched/core: Require cpu_active() in select_task_rq(), for user tasks")
    >
    > Fix it like so?
    >
    > sched: Allow pinned user tasks to be awakened to the CPU they pinned
    >
    > Since 7af443ee16976, select_fallback_rq() will BUG() if the CPU to
    > which a task has pinned itself and pinned becomes !cpu_active()
    > while it slept. Serving a 10 megaton eviction notice is neither
    > helpful nor required, the task will migrate when it can do so.

    This seems to fix the issue that I was seeing. Thanks!

    I'll add this to my repo as well.

    -- Steve

    >
    > Signed-off-by: Mike Galbraith <efault@gmx.de>
    > ---
    > kernel/sched/core.c | 2 +-
    > 1 file changed, 1 insertion(+), 1 deletion(-)
    >
    > --- a/kernel/sched/core.c
    > +++ b/kernel/sched/core.c
    > @@ -980,7 +980,7 @@ static inline bool is_cpu_allowed(struct
    > if (!cpumask_test_cpu(cpu, p->cpus_ptr))
    > return false;
    >
    > - if (is_per_cpu_kthread(p))
    > + if (is_per_cpu_kthread(p) || __migrate_disabled(p))
    > return cpu_online(cpu);
    >
    > return cpu_active(cpu);

    \
     
     \ /
      Last update: 2018-08-22 18:18    [W:2.807 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site