On Tue, Aug 10, 2021 at 04:48:59PM -0300, Daniel Henrique Barboza wrote: > > > On 8/10/21 1:17 AM, David Gibson wrote: > > On Mon, Aug 09, 2021 at 10:10:56AM -0300, Daniel Henrique Barboza wrote: > > > EBB powerpc kernel test 'multi_counter_test' uses PM_CMPLU_STALL events > > > that we do not support. These events are related to CPU stalled/wasted > > > cycles while waiting for resources, cache misses and so on. > > > > > > Unlike the 0xFA event added previously, there's no available equivalent > > > for us to use, and at this moment we can't sample those events as well. > > > What we can do is mock those events as if we were calculating them. > > > > > > This patch implements PM_CMPLU_STALL, PM_CMPLU_STALL_FXU, > > > PM_CMPLU_STALL_OTHER_CMPL and PM_CMPLU_STALL_THRD mock events by giving > > > them a fixed amount of the total elapsed cycles. > > > > > > The chosen sample values for these events (25% of total cycles for > > > PM_CMPLU_STALL and 5% for the other three) were chosen at random and has > > > no intention of being truthful with what a real PowerPC hardware would > > > give us. Our intention here is to make 'multi_counter_test' EBB test > > > pass. > > > > Hmm. I guess these mock values make sense for getting the kernel > > tests to pass, but I'm not sure if it's a good idea in general. Would > > we be better off just reporting 0 always - that would be a strong hint > > to someone attempting to analyze results that something is fishy (in > > this case that they don't actually have a real CPU). > > We can drop this patch and I'll add a note in the docs that the EBB kernel > test 'multi_counter_test' fails because the PMU does not implement STALL > events.
Sounds good for now. We can reconsider this if we have a specific
justification for it.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
