Slow fork issue - Win x64

[Reini Urban]

2010/10/10 Nicole Hamilton:
> Jarkko Häkkinen wrote:
>> I'm getting rather similar results on my Cygwin 1.7.1, Windows 7 as
>> evidenced by the figures below.
>>
>> [13:41:50 ~]$ while (true); do date; done | uniq -c
>>       5 Tue Feb 16 14:00:09 FLEST 2010
>>       7 Tue Feb 16 14:00:10 FLEST 2010
>>       9 Tue Feb 16 14:00:11 FLEST 2010
>>       9 Tue Feb 16 14:00:12 FLEST 2010
>
> Oh, my.  Here's what I get with 64-bit Hamilton C shell on Windows 7 on a
> 2.67GHz Core i7:
>
> 10 C% date +"%a %b %d %H:%M:%S %Z %Y"
> Sun Oct 10 12:03:31 PDT 2010
> 11 C% while (1) !!; end | uniq -c
> while ( 1 ) date +"%a %b %d %H:%M:%S %Z %Y" ; end | uniq -c
>  164 Sun Oct 10 12:03:51 PDT 2010
>  170 Sun Oct 10 12:03:52 PDT 2010
>  169 Sun Oct 10 12:03:53 PDT 2010
>  169 Sun Oct 10 12:03:54 PDT 2010
>
> Here's what I get on a MacBook with a 2.4GHz Core 2 Duo, again running
> 64-bit code on Win7:
>
> 8 C% while ( 1 ) date +"%a %b %d %H:%M:%S %Z %Y" ; end | uniq -c
>  17 Sun Oct 10 12:17:21 PDT 2010
>  84 Sun Oct 10 12:17:22 PDT 2010
>  77 Sun Oct 10 12:17:23 PDT 2010
>  78 Sun Oct 10 12:17:24 PDT 2010
>
> But this is running native, using threads instead of a fork emulation.

And native linux 64-bit bash has these:

rurban@deblap:~$ while (true); do date; done | uniq -c
    228 Mon Okt 11 20:12:51 CEST 2010
    250 Mon Okt 11 20:12:52 CEST 2010
    221 Mon Okt 11 20:12:53 CEST 2010
    200 Mon Okt 11 20:12:54 CEST 2010
    183 Mon Okt 11 20:12:55 CEST 2010
    179 Mon Okt 11 20:12:56 CEST 2010
    165 Mon Okt 11 20:12:57 CEST 2010
    150 Mon Okt 11 20:12:58 CEST 2010
    146 Mon Okt 11 20:12:59 CEST 2010

We know bash is slow, so
rurban@deblap:~$ dash
$ while (true); do date; done | uniq -c
    232 Mon Okt 11 20:14:51 CEST 2010
    508 Mon Okt 11 20:14:52 CEST 2010
    508 Mon Okt 11 20:14:53 CEST 2010
    510 Mon Okt 11 20:14:54 CEST 2010
    507 Mon Okt 11 20:14:55 CEST 2010
    511 Mon Okt 11 20:14:56 CEST 2010
    502 Mon Okt 11 20:14:57 CEST 2010
    508 Mon Okt 11 20:14:58 CEST 2010

-- 
Reini Urban
http://phpwiki.org/           http://murbreak.at/

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