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Re: Slow fork issue - Win x64



Jarkko Häkkinen a écrit :

I'm getting rather similar results on my Cygwin 1.7.1, Windows 7 as evidenced
by the figures below. Upgraded from a dual core Windows XP to a quad core i7
Windows 7 causing my cygwin performance to plummet. Even the bash
auto-completion is so annoyingly sluggish that it makes the shell virtually
unusable.


For me, there's no choice between whether or not to make the transition from
XP to 7 as we're using the latest DirectX technology. Hope somebody will
figure this out.

[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
      9 Tue Feb 16 14:00:13 FLEST 2010
      9 Tue Feb 16 14:00:14 FLEST 2010
      9 Tue Feb 16 14:00:15 FLEST 2010
      9 Tue Feb 16 14:00:16 FLEST 2010
      6 Tue Feb 16 14:00:17 FLEST 2010
      5 Tue Feb 16 14:00:18 FLEST 2010
      9 Tue Feb 16 14:00:19 FLEST 2010



prashantv wrote:
My speeds are even slower than those posted:

Prashant@HOME [~]
$ while (true); do date; done | uniq -c
      1 Tue Jan 20 22:25:50 AUSEDT 2009
      1 Tue Jan 20 22:25:51 AUSEDT 2009
      2 Tue Jan 20 22:25:52 AUSEDT 2009
      1 Tue Jan 20 22:25:53 AUSEDT 2009
      2 Tue Jan 20 22:25:54 AUSEDT 2009
      2 Tue Jan 20 22:25:55 AUSEDT 2009
      1 Tue Jan 20 22:25:56 AUSEDT 2009
      3 Tue Jan 20 22:25:57 AUSEDT 2009
      1 Tue Jan 20 22:25:58 AUSEDT 2009
      2 Tue Jan 20 22:25:59 AUSEDT 2009
      2 Tue Jan 20 22:26:00 AUSEDT 2009
      2 Tue Jan 20 22:26:01 AUSEDT 2009

I am running cygwin 1.5.25, Windows 2008 x64 on a Intel Core 2 @ 2.13ghz.
One CPU is maxed to 100% when forking. This speed explained why opening
bash took as long as 10 seconds, and I wanted to find out why it was so
slow.

Is it possible to profile the implementation easily?

bash is not an efficient shell :


while : ; do date; done | uniq -c

      5 Thu Feb 18 01:03:30     2010
      8 Thu Feb 18 01:03:31     2010
      8 Thu Feb 18 01:03:32     2010
      9 Thu Feb 18 01:03:33     2010
      8 Thu Feb 18 01:03:34     2010
      9 Thu Feb 18 01:03:35     2010
      8 Thu Feb 18 01:03:36     2010
      5 Thu Feb 18 01:03:37     2010

let's try pdksh (well, not really more efficient) :

      7 Thu Feb 18 01:03:38     2010
      9 Thu Feb 18 01:03:39     2010
      8 Thu Feb 18 01:03:40     2010
      8 Thu Feb 18 01:03:41     2010
      8 Thu Feb 18 01:03:42     2010
      9 Thu Feb 18 01:03:43     2010
      8 Thu Feb 18 01:03:44     2010
      8 Thu Feb 18 01:03:45     2010
      8 Thu Feb 18 01:03:46     2010
      7 Thu Feb 18 01:03:47     2010

and ksh 93 :

      8 Thu Feb 18 01:03:59     2010
      7 Thu Feb 18 01:04:00     2010
     12 Thu Feb 18 01:04:01     2010
     12 Thu Feb 18 01:04:02     2010
     12 Thu Feb 18 01:04:03     2010
     12 Thu Feb 18 01:04:04     2010
     12 Thu Feb 18 01:04:05     2010
     12 Thu Feb 18 01:04:06     2010
     12 Thu Feb 18 01:04:07     2010
     12 Thu Feb 18 01:04:08     2010

ksh88 is not so bad :

      7 Thu Feb 18 01:06:47     2010
      6 Thu Feb 18 01:06:48     2010
     10 Thu Feb 18 01:06:49     2010
      9 Thu Feb 18 01:06:50     2010
      9 Thu Feb 18 01:06:51     2010
     10 Thu Feb 18 01:06:52     2010
      9 Thu Feb 18 01:06:53     2010
      9 Thu Feb 18 01:06:54     2010
      8 Thu Feb 18 01:06:55     2010
      9 Thu Feb 18 01:06:56     2010

tests realised under cygwin 1.7 on a Q6600 in 32 bit mode (around 30% of cpu usage)

Cordialement,

Cyrille Lefevre
--
mailto:Cyrille.Lefevre-lists@laposte.net



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