Re: [tip:sched/balancing] sched: Add comments tofind_busiest_group() function
From: Ingo Molnar
Date: Wed Mar 25 2009 - 12:17:35 EST
* Ray Lee <ray-lk@xxxxxxxxxxxxx> wrote:
> This commit says it's just adding comments, but...
>
> On Wed, Mar 25, 2009 at 5:30 AM, Gautham R Shenoy <ego@xxxxxxxxxx> wrote:
> > Commit-ID: b7bb4c9bb01941fe8feb653f3410e7ed0c9bb786
> > Gitweb: http://git.kernel.org/tip/b7bb4c9bb01941fe8feb653f3410e7ed0c9bb786
> > Author: Gautham R Shenoy <ego@xxxxxxxxxx>
> > AuthorDate: Wed, 25 Mar 2009 14:44:27 +0530
> > Committer: Ingo Molnar <mingo@xxxxxxx>
> > CommitDate: Wed, 25 Mar 2009 13:28:30 +0100
> >
> > sched: Add comments to find_busiest_group() function
> >
> > Impact: cleanup
> >
> > Add /** style comments around find_busiest_group(). Also add a few
> > explanatory comments.
>
> ...but there are actual code changes. Hard to know if you intended to
> do that and forgot to changelog it, or if it's an unexpected hunk that
> accidentally got included:
>
> > if (balance && !(*balance))
> > goto ret;
> >
> > - if (!sds.busiest || sds.this_load >= sds.max_load
> > - || sds.busiest_nr_running == 0)
> > + if (!sds.busiest || sds.busiest_nr_running == 0)
> > + goto out_balanced;
> > +
> > + if (sds.this_load >= sds.max_load)
> > goto out_balanced;
> >
> > sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr;
> >
> > - if (sds.this_load >= sds.avg_load ||
> > - 100*sds.max_load <= sd->imbalance_pct * sds.this_load)
> > + if (sds.this_load >= sds.avg_load)
> > + goto out_balanced;
> > +
> > + if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
> > goto out_balanced;
> >
> > sds.busiest_load_per_task /= sds.busiest_nr_running;
yeah.
Note that it does not actually change the resulting logic, it splits
out an over-long (and hard to read) series of conditions into an
equivalent set of two if() statements. [the first one changes the
order of two conditions - but that is harmless]
It indeed would have been nice to declare this in the changelog
though.
Ingo
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