[LITMUS^RT] prop/sched-domains

[Glenn Elliott]

Rats. I knew that commas would be a problem, but I thought we’d be okay up to 64 CPUs on 64-bit systems.  I didn’t know that the commas started at 32.  (We can only test up to 24 CPUs at UNC.)  I’m happy to take a look, but are you pressed to get a fix before RTSS?

Thanks,
Glenn


On May 5, 2014, at 11:15 AM, Björn Brandenburg <bbb at mpi-sws.org> wrote:

> Hi Glenn,
> 
> with NR_CPUS=64, I'm seeing a problem with the new sched-domains code. Specifically: 
> 
>> # cat /proc/litmus/domains/6
>> 00000000,00000040
> 
> The kernel prints a separating comma for readability when printing "long" bitfields.
> 
> 	https://github.com/LITMUS-RT/litmus-rt/blob/master/lib/bitmap.c#L375
> 
> The code in liblitmus does not expect this.
> 
> 	https://github.com/LITMUS-RT/liblitmus/blob/master/src/migration.c#L48
> 
> Seems to me that either the userspace part needs to be expanded to accept the kernel's use of a separator, or the kernel needs to not use cpumask_scnprintf() to populate the /proc files.
> 
> 	https://github.com/LITMUS-RT/litmus-rt/blob/master/litmus/litmus_proc.c#L444
> 
> If you get a chance, could you please have a look at this?
> 
> Thanks,
> Björn
>