This needs a little perspective, as I couldn't clone the repository (and
you know that), all I had was this announcement, so using the patch
descriptions now as defense is unfair by you.
In this announcement you make relatively few references how this relates
to my work. Maybe someone else can show me how to read that announcement
differently, but IMO the casual reader is likely to get the impression,
that you only picked some minor cleanups from my patch, but it's rather
unclear that you already reimplemented key aspects of my patch. Don't
blame me for your own ambiguity.
Let's compare this to the relevant part of the announcement:
| The ->vruntime metric is similar to the ->time_norm metric used by
| Roman's patch (and both are losely related to the already existing
| sum_exec_runtime metric in CFS), it's in essence the sum of CPU time
| executed by a task, in nanoseconds - weighted up or down by their nice
| level (or kept the same on the default nice 0 level). Besides this basic
| metric our implementation and math differs from RFS.
In the patch you are more explicit about the virtual time aspect, in the
announcement you're less clear that it's all based on the same idea and
somehow it's important to stress the point that "implementation and math
differs", which is not untrue, but your forget to mention that the
differences are rather small.
This is ridiculous, I asked you multiple times to explain to me some of
the differences relative to CFS as response to the splitup requests. Not
once did you react, you didn't even ask what I'd like to know
specifically.
I never claimed to understand every detail of CFS, I can _guess_ what
_might_ have been intended, but from that it's impossible to know for
certain how important they are. Let's take this patch fragment:
- /*
- * Fix up delta_fair with the effect of us running
- * during the whole sleep period:
- */
- if (sched_feat(SLEEPER_AVG))
- delta_fair = div64_likely32((u64)delta_fair * load,
- load + se->load.weight);
-
- delta_fair = calc_weighted(delta_fair, se);
You simply remove this logic, without ever explaining what it was really
good for. There is no indication how it has been replaced. AFAICT the
comment refers to the calc_weighted() call, which is not the problem.
I can _guess_ that it was meant to scale the bonus based on cpu load, what
I can't guess from this is why this logic was added in first place, _why_
it was neccessary.
It had been easy for me to simply remove this as well, but I had preferred
to _know_ what the motivation for this logic was, so I can take it into
account in my patch.
bye, Roman
-
