The algorithm is supposed to work as follows:
in order to prevent starvation, when a new client starts being served we
record the start time and reset the counter of bytes served.
We then switch to a new client after a certain amount of time or bytes,
even if the current one still has pending requests.
To avoid charging a new client the time of the first seek,
we start counting time when the first request is served.
Unfortunately a bug in the previous version of the code failed
to set the start time in certain cases, resulting in some processes
exceeding their timeslice.
The fix (in this patch) is trivial, though it took a while to find
out and replicate the bug.
Thanks to Tommaso Caprai for investigating and fixing the problem.
Submitted by: Tommaso Caprai
MFC after: 1 week
in a device independent manner. Also include an example anticipatory
scheduler, gsched_rr, which gives very nice performance improvements
in presence of competing random access patterns.
This is joint work with Fabio Checconi, developed last year
and presented at BSDCan 2009. You can find details in the
README file or at
http://info.iet.unipi.it/~luigi/geom_sched/
