Messages in this thread Patch in this message | | | Date | Tue, 25 May 2021 13:06:55 +0000 | From | Quentin Perret <> | Subject | Re: [PATCH v2 3/3] PM / EM: Skip inefficient OPPs |
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Hi Lukasz,
On Tuesday 25 May 2021 at 12:03:14 (+0100), Lukasz Luba wrote: > That's a few more instructions to parse the 'flags' filed. I'm not sure > if that brings speed improvements vs. if we not parse and have bool > filed with a simple looping. The out-of-order core might even suffer > from this parsing and loop index manipulations...
I'm not sure what you mean about parsing here? I'm basically suggesting to do something along the lines of:
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index daaeccfb9d6e..f02de32d2325 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -128,13 +128,11 @@ struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd,
for (i = 0; i < pd->nr_perf_states; i++) { ps = &pd->table[i]; - if (ps->flags & EM_PERF_STATE_INEFFICIENT) - continue; if (ps->frequency >= freq) break; }
- return ps; + return &pd->table[ps->next_efficient_idx]; }
What would be wrong with that?
Thanks, Quentin
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