Date: Tue, 08 Jul 2003 18:21:58 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: David Xu <davidxu@viatech.com.cn> Cc: threads@freebsd.org Subject: Re: libc_r silliness Message-ID: <XFMail.20030708182158.jhb@FreeBSD.org> In-Reply-To: <001201c3459c$f0f66480$0701a8c0@tiger>
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On 08-Jul-2003 David Xu wrote:
>
> ----- Original Message -----
> From: "John Baldwin" <jhb@FreeBSD.org>
> To: "Terry Lambert" <tlambert2@mindspring.com>; <deischen@FreeBSD.org>
> Cc: <threads@FreeBSD.org>
> Sent: Tuesday, July 08, 2003 9:23 PM
> Subject: Re: libc_r silliness
>
>
>> On Tuesday 08 July 2003 06:35 am, Terry Lambert wrote:
>> > Daniel Eischen wrote:
>> > > On Mon, 7 Jul 2003, John Baldwin wrote:
>> > > > > I don't really know how to handle this. We can wrap
>> > > > > sched_get_priority_{min,max}(), but how do we know whether
>> > > > > the application wants process priorities or thread
>> > > > > priorities?
>> > > >
>> > > > Ugh. Perhaps the manpage should at least be updated to not
>> > > > reference the macros. What does POSIX say about the confusion
>> > > > between sched_get_priority_{min,max}?
>> > >
>> > > Sure, update the man pages if you want ;-)
>> > >
>> > > I have not found anything yet regarding sched_get_priority_{min,max}
>> > > confusion in the POSIX spec...
>> >
>> > http://www.opengroup.org/onlinepubs/007904975/functions/sched_get_priority_
>> >max.html
>> >
>> > The functions take a policy parameter; they are supposed to
>> > return "appropriate" values, which I took to mean "appropriate
>> > to the policy parameter supplied at the time they were called":
>> >
>> > int sched_get_priority_max(int policy);
>> > int sched_get_priority_min(int policy);
>> >
>> > The sched_get_priority_max() and sched_get_priority_min()
>> > functions shall return the appropriate maximum or minimum,
>> > respectively, for the scheduling policy specified by policy.
>>
>> Yes, but in a multithreaded program when I call
>> sched_get_priority_max(SCHED_RR), does that tell me the maximum process
>> SCHED_RR priority for use with sched_setschedparam() or does it tell me the
>> maximum thread SCHED_RR priority for use with pthread_setschedparam()?
>>
> See page:
> http://www.opengroup.org/onlinepubs/007904975/basedefs/sched.h.html
> They are marked with 'TPS' code, so they are applied to thread scheduling.
> Otherwise, they should be marked with 'PS' code.
> This is the code page:
> http://www.opengroup.org/onlinepubs/007904975/help/codes.html
Hmm, then why do we have these in the kernel? Shouldn't these be
implemented in each thread library instead? Was this another one
of the hacks to make LinuxThreads work? It sounds like each threading
library should provide these functions and the kernel has no business
supplying them.
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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