Re: Why is taskset still not in util-linux?

[Eliot Moss <moss@cs.umass.edu>]

On 3/16/2020 7:34 PM, Mark Geisert wrote:
 > Mark Geisert wrote:
 >> Eliot Moss wrote:
 >>>
 >>> Dear cygwin-ers --
 >>>
 >>> Something I had asked about a while ago was the absence os taskset in cygwin's
 >>> util-linux.  At the time, it was pointed out that the necessary get/set
 >>> affinity library/system calls were not yet supported.  These were added a
 >>> while ago, so it would seem that taskset ought to work.  In fact, I think
 >>> someone got it going on their own.  Can we add it to util-linux now,
 >>> officially?  I think this was intended but perhaps was overlooked or
 >>> something.
 >>
 >> Report noted; thanks.  A solution is being worked.
 >
 > There's been no forward progress on this.  If you're comfortable getting the util-linux source
 > package through Cygwin setup*.exe, you can follow the steps shown in
 > https://cygwin.com/pipermail/cygwin-apps/2020-March/039855.html to build (with cygport) a local copy
 > of util-linux that includes a taskset.exe you can move into /usr/local/bin, for example.
 >
 > You might try that route if you're up for it.  Feel free to ask questions here if you hit a snag.
 > HTH,

Thank you, Mark.  I decided to give it a try and got some distance, but hit a snag.

First, I had to change configure.ac to add control to disable ionice (Cygwin
does not support a required syscall) while still trying to build taskset.
Previously taskset and ionice (and one other program) were controlled by the
single --enable-schedutils.

Now, including sched.h does not provide the prototypes for sched_getaffinity,
etc.  I found a previous post that suggests we need to do -D_GNU_SOURCE for it
to work.  I am not sure of the best place to stick that, but I will see about
maybe a one line patch to taskset.c or something.

Regards - Eliot