years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
have been in the base for a while, so the gymnastics here aren't
needed. In addition, the bugs in subr_disk.c have been fixed since
2009, so there's no need for an identical copy of it in the tree
anymore. There's really no need to binary patch g_io_request, so let's
get rid of the code (not compiled in anymore) lest others think it is
a good idea.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
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/
