| Submitter | Konrad Eisele |
|---|---|
| Date | April 19, 2012, 9:22 a.m. |
| Message ID | <1334827362-3434-1-git-send-email-konrad@gaisler.com> |
| Download | mbox | patch |
| Permalink | /patch/153710/ |
| State | RFC |
| Delegated to: | David Miller |
| Headers | show |
Comments
Added a few more people - as this patch touches a core file. I expect we have an issue on sparc32 - that manifest in this bug. But I do not know this code at all. Sam On Thu, Apr 19, 2012 at 11:22:42AM +0200, Konrad Eisele wrote: > The stopper thread for CPU > 0 (at least in sparc32) > has on initialization task_cpu() set to zero even > for CPUs > 0. The patch explicitly checks weather the > CPU is allowed to run on the cpu that task_cpu() > return or changes the return cpu. > > Signed-off-by: Konrad Eisele <konrad@gaisler.com> > --- > kernel/sched/stop_task.c | 9 ++++++++- > 1 files changed, 8 insertions(+), 1 deletions(-) > > diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c > index 7b386e8..9201866 100644 > --- a/kernel/sched/stop_task.c > +++ b/kernel/sched/stop_task.c > @@ -13,7 +13,14 @@ > static int > select_task_rq_stop(struct task_struct *p, int sd_flag, int flags) > { > - return task_cpu(p); /* stop tasks as never migrate */ > + int ccpu, cpu , dcpu; > + ccpu = cpu = task_cpu(p); > + if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))) { > + cpu = cpumask_first(tsk_cpus_allowed(p)); > + if (cpu >= nr_cpu_ids) > + cpu = ccpu; > + } > + return cpu; > } > #endif /* CONFIG_SMP */ > > -- > 1.6.1.3 > -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Konrad Eisele <konrad@gaisler.com> Date: Thu, 19 Apr 2012 11:22:42 +0200 > The stopper thread for CPU > 0 (at least in sparc32) > has on initialization task_cpu() set to zero even > for CPUs > 0. The patch explicitly checks weather the > CPU is allowed to run on the cpu that task_cpu() > return or changes the return cpu. > > Signed-off-by: Konrad Eisele <konrad@gaisler.com> Posting a patch to generic code like this only to the Sparc list isn't going to drive us forward to a solution and will not involve the people who need to help you look into this problem. Therefore you need to post this with at least linux-kernel and the scheduler maintainer's CC:'d. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Patch
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index 7b386e8..9201866 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -13,7 +13,14 @@ static int select_task_rq_stop(struct task_struct *p, int sd_flag, int flags) { - return task_cpu(p); /* stop tasks as never migrate */ + int ccpu, cpu , dcpu; + ccpu = cpu = task_cpu(p); + if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))) { + cpu = cpumask_first(tsk_cpus_allowed(p)); + if (cpu >= nr_cpu_ids) + cpu = ccpu; + } + return cpu; } #endif /* CONFIG_SMP */
The stopper thread for CPU > 0 (at least in sparc32) has on initialization task_cpu() set to zero even for CPUs > 0. The patch explicitly checks weather the CPU is allowed to run on the cpu that task_cpu() return or changes the return cpu. Signed-off-by: Konrad Eisele <konrad@gaisler.com> --- kernel/sched/stop_task.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-)