From owner-freebsd-arch  Sun Feb 17 16: 7:19 2002
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Date: Mon, 18 Feb 2002 11:06:51 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: Poul-Henning Kamp <phk@critter.freebsd.dk>
Cc: Matthew Dillon <dillon@apollo.backplane.com>,
	Terry Lambert <tlambert2@mindspring.com>,
	Julian Elischer <julian@elischer.org>,
	Alfred Perlstein <bright@mu.org>, <arch@FreeBSD.ORG>,
	<jhb@FreeBSD.ORG>, <peter@wemm.org>, <jake@locore.ca>
Subject: Re: gettimeofday() and crhold()/crfree() (was Re: gettimeofday()and
 copyout(). Is copyout() MPSAFE on non-i386 archs? ) 
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On Sun, 17 Feb 2002, Poul-Henning Kamp wrote:

> Peter and I actually had a sligthly different idea:
>
> Add a new syscall:
>
> 	int getkernstuff(struct kernstuff *kp);
>
> 	struct kernstuff {
> 		u_int32_t	version;
> 		pid_t		pid, ppid;
> 		uid_t		uid, euid ...
> 		gid_t		gid, guid ...
> 		signal masks
> 		...
> 	}
>
> The idea here being that the userland process registers a single
> static structure with the kernel.  Inside libc, this structure
> can be used to speed up signal processing and much more.

This might have been useful in 1980, but gettimeofday() in practice
has 10^6 times as much resolution now.  However, updating the kernel
struct 10^6 times per second is beyond the capabilities of even current
machiens, in software.  It is possible in hardware of course.

Bruce


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