Messages in this thread | | | Date | Thu, 31 Jul 2003 19:06:36 -0400 | From | Joe Korty <> | Subject | Re: [PATCH] protect migration/%d etc from sched_setaffinity |
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> On Thu, 2003-07-31 at 15:46, Joe Korty wrote: > > > Lock out users from changing the cpu affinity of those per-cpu system > > daemons which cannot survive such a change, such as migration/%d. > > > > Passes basic handtest of sched_setaffinity(2) on various locked and > > unlocked processes on a i386, otherwise untested except by eyeball. > > > > Except for one line in i386, no arch needed any changes to support > > this patch. > > I have been wondering what to do about processor affinity and kernel > threads. I just concluded "only root can change it, and we can let root > stab herself if she really wants to." > > But if this is really an issue, why not just do: > > ret = -EINVAL; > if (!p->mm) > goto out_unlock; > > in sys_sched_setaffinity ? > > Robert Love
It's not all system daemons, just some of them that need protection.
Keeping the set of locked-down daemons to the smallest possible is important when one wants to 'set aside' cpus for use only by specific, need-the-lowest-latency-possible realtime applications.
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