On Tue, 2021-11-09 at 13:53 +0000, Lukasz Luba wrote: > Hi Srinivas, > > On 11/9/21 1:23 PM, Srinivas Pandruvada wrote: > > Hi Lukasz, > > > > On Tue, 2021-11-09 at 12:39 +0000, Lukasz Luba wrote: > > > Hi Ricardo, > > > > > > > > > On 11/6/21 1:33 AM, Ricardo Neri wrote: > > > > From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > > > > > > > > Add a new netlink event to notify change in CPU capabilities in > > > > terms of > > > > performance and efficiency. > > > > > > Is this going to be handled by some 'generic' tools? If yes, > > > maybe > > > the values for 'performance' might be aligned with capacity > > > [0,1024] ? Or are they completely not related so the mapping is > > > simply impossible? > > > > > > > That would have been very useful. > > > > The problem is that we may not know the maximum performance as > > system > > may be booting with few CPUs (using maxcpus kernel command line) > > and > > then user hot adding them. So we may need to rescale when we get a > > new > > maximum performance CPU and send to user space. > > > > We can't just use max from HFI table at in instance as it is not > > necessary that HFI table contains data for all CPUs. > > > > If HFI max performance value of 255 is a scaled value to max > > performance CPU value in the system, then this conversion would > > have > > been easy. But that is not. > > I see. I was asking because I'm working on similar interface and > just wanted to understand your approach better. In my case we > would probably simply use 'capacity' scale, or more > precisely available capacity after subtracting 'thermal pressure' > value. > That might confuse a generic tool which listens to these socket > messages, though. So probably I would have to add a new > THERMAL_GENL_ATTR_CPU_CAPABILITY_* id > to handle this different normalized across CPUs scale. I can add a field capacity_scale. In HFI case it will always be 255. In your cases it will 1024.
