Re: [Lse-tech] Re: [PATCH] cpusets+hotplug+preepmt broken

Paul Jackson
2005-05-14T02:59:16Z

Dipankar, replying to pj:
> > What part of what I wrote are you saying "No" to?
>
> The question right above "No" :)

Well ... that was less than obvious. You quoted too much, and
responded with information about other semaphores, not about
why other duties of _this_ semaphore made such a rename wrong.

Fortunately, Nathan clarified matters.

So how would you, or Srivatsa or Nathan, respond to my more substantive
point, to repeat:

Srivatsa, replying to Dinakar:
> This in fact was the reason that we added lock_cpu_hotplug
> in sched_setaffinity.

Why just in sched_setaffinity()? What about the other 60+ calls to
set_cpus_allowed(). Shouldn't most of those calls be checking that the
passed in cpus are online (holding lock_cpu_hotplug while doing all
this)? Either that, or at least handling the error from
set_cpus_allowed() if the requested cpus end up not being online? I see
only 2 set_cpus_allowed() calls that make any pretense of examining the
return value.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@engr.sgi.com> 1.650.933.1373, 1.925.600.0401