Date: Mon, 16 Oct 2000 22:33:44 -0400 From: "Daniel M. Eischen" <eischen@vigrid.com> To: current@freebsd.org Subject: Re: Recent thread changes Message-ID: <39EBBA88.684E3178@vigrid.com> References: <Pine.SUN.3.91.1001014234955.25430B-100000@pcnet1.pcnet.com> <200010170201.e9H21GF53460@vashon.polstra.com>
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jdp@polstra.com wrote: > > In article > <Pine.SUN.3.91.1001014234955.25430B-100000@pcnet1.pcnet.com>, Daniel > Eischen <eischen@vigrid.com> wrote: > > > For SCHED_FIFO and SCHED_RR, we don't have a problem because both > > the threads library and kernel now agree that the range is 0..31. > > SCHED_OTHER is a problem because the threads library treats > > SCHED_OTHER as SCHED_RR with range 0..31. The kernel treats > > SCHED_OTHER traditionally with range -20..20. > > As long as the only problem area is SCHED_OTHER, we are arguably > OK. SCHED_OTHER is almost entirely implementation-defined; it can > do practically anything. More specifically, section 13.5.2.2 (the > detailed description of pthread_[sg]etschedparam) says: > > The policy parameter may have the value SCHED_OTHER, SCHED_FIFO, > or SCHED_RR. The scheduling parameters for the SCHED_OTHER policy > are implementation defined. The SCHED_FIFO and SCHED_RR policies > shall have a single scheduling parameter sched_priority. > > I think it would be slightly less surprising if our implementation of > SCHED_OTHER used thread priorities in the range -20..20 just the same > as processes. But in my opinion POSIX doesn't require that. I tend to agree. When you consider that you can mix PTHREAD_SCOPE_SYSTEM threads with PTHREAD_SCOPE_PROCESS threads, it seems logical that you'd want the priority ranges in both the threads library and the kernel to agree. I would just rather see 0..31 instead of -20..20. We'll have to address this issue in the near future. -- Dan Eischen To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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