Re: CONFIG_MODVERSIONS problem identified

From: Frank van Maarseveen (F.vanMaarseveen@inter.NL.net)
Date: Thu Jul 27 2000 - 14:00:25 EST


On Thu, Jul 27, 2000 at 03:57:21AM +0200, Mikael Pettersson wrote:
> Possible solutions:
> A. Increase the resolution of file modification times to microseconds.
> Probably not practical right now (2.4 release, glibc binary compat.),
> but IMHO necessary in the near future.
This is not very difficult and has been done already on other UNIXes,
at least on OSF and Solaris many years ago. The trick is to stash micro
or nanosecond fractions in the spare fields of the struct stat. Really,
second resolution is no good these days when small source files can be
compiled in a fraction of a second:

        iapetus ~ cat hello.c
        #include <stdio.h>
        int main(void)
        {
                printf("Hello world!\n");
                return 0;
        }
        iapetus ~ time gcc -c hello.c
        0.04user 0.02system 0:00.04elapsed 127%CPU (0avgtext+0avgdata 0maxresident)k
        0inputs+0outputs (680major+200minor)pagefaults 0swaps
        iapetus ~ time gcc -c hello.c
        0.04user 0.01system 0:00.04elapsed 106%CPU (0avgtext+0avgdata 0maxresident)k
        0inputs+0outputs (680major+200minor)pagefaults 0swaps

Internal times on NFS already have microsecond resolution (struct timeval).

-- 
Frank

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