[Pdbg] [PATCH v2 2/2] main: Address by linux CPU number with PPC host backend

Amitay Isaacs amitay at ozlabs.org
Mon Jul 16 12:35:46 AEST 2018


On Sun, 2018-07-15 at 16:42 +1000, Michael Neuling wrote:
> On Fri, 2018-07-13 at 16:34 +1000, Amitay Isaacs wrote:
> > On Fri, 2018-07-13 at 16:21 +1000, Michael Neuling wrote:
> > > With the PPC host backend used for HTM it's difficult to match up
> > > the
> > > hardware numbers used pdbg with linux CPU numbers that people
> > > want to
> > > affinitise a workload against (ie. taskset -c <cpu number>).
> > > 
> > > This adds a new "-l <cpu>" options so users can address the CPU
> > > to
> > > target using linux CPU numbers. This is only available when using
> > > the
> > > host backend on POWER machines.
> > 
> > Is -l mutually exlusive with -p?
> 
> Yes, they are mutually exclusive
> 
> > Or you expect "... -p 13 -l 1 ... " to work?
> 
> I would not expect that to work but I don't have an explicit check
> for it right
> now.  We should probably add something.
> 
> > If they are mutually exclusive, we can just map l_list to p_list
> > via
> > pir_map().
> 
> I think it l_list would need to map to p_list, c_list and t_list...
> not justp_list.  
> 
> I end up just doing the mapping from l_list to thread/chip/processor
> sel.

I realized that "-l <cpu>" should really be mapping to hardware threads
and not just hardware processors.

So l_list should be declared as:

   int l_list[MAX_PROCESSORS * MAX_CHIPS * MAX_THREADS];

It should enable appropriately selected processors/cores/threads.

Amitay.
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