Performance degradation between Cygwin 1.7.7-1 and 1.5.24-2

[marco atzeri]

On 2/6/2012 2:08 PM, Jaswinder Bhamra wrote:
> Hi,
>
> We are experiencing performance degradation between Cygwin version
> 1.7.7-1 and 1.5.24-2.
>
> Recently, we have upgraded from Cygwin version 1.5.24-2 to version
> 1.7.7-1. The simple test brings forward the performance degradation in
> version 1.7.7-1 over 1.5.24-2.
>
> <On Cygwin version 1.5.24-2>
> bash-3.2$ while [ 1 ]; do date; done | uniq -c
>    40 Mon Feb  6 17:58:13 2012
>    65 Mon Feb  6 17:58:14 2012
>    66 Mon Feb  6 17:58:15 2012
>    65 Mon Feb  6 17:58:16 2012
>    66 Mon Feb  6 17:58:17 2012
>    65 Mon Feb  6 17:58:18 2012
>    66 Mon Feb  6 17:58:19 2012
>    65 Mon Feb  6 17:58:20 2012
>    65 Mon Feb  6 17:58:21 2012
>    66 Mon Feb  6 17:58:22 2012
>    65 Mon Feb  6 17:58:23 2012
>    66 Mon Feb  6 17:58:24 2012
>    64 Mon Feb  6 17:58:25 2012
>    65 Mon Feb  6 17:58:26 2012
>    66 Mon Feb  6 17:58:27 2012
>    66 Mon Feb  6 17:58:28 2012
>    65 Mon Feb  6 17:58:29 2012
>    65 Mon Feb  6 17:58:30 2012
>
> bash-3.2$
>
> <On Cygwin version 1.7.7-1>
> # while [ 1 ]; do date; done | uniq -c
>       16 Mon Feb  6 17:58:41 IST 2012
>       49 Mon Feb  6 17:58:42 IST 2012
>       50 Mon Feb  6 17:58:43 IST 2012
>       50 Mon Feb  6 17:58:44 IST 2012
>       49 Mon Feb  6 17:58:45 IST 2012
>       50 Mon Feb  6 17:58:46 IST 2012
>       50 Mon Feb  6 17:58:47 IST 2012
>       49 Mon Feb  6 17:58:48 IST 2012
>       49 Mon Feb  6 17:58:49 IST 2012
>       49 Mon Feb  6 17:58:50 IST 2012
>       50 Mon Feb  6 17:58:51 IST 2012
>       50 Mon Feb  6 17:58:52 IST 2012
>       49 Mon Feb  6 17:58:53 IST 2012
>       50 Mon Feb  6 17:58:54 IST 2012
>       50 Mon Feb  6 17:58:55 IST 2012
>       49 Mon Feb  6 17:58:56 IST 2012
>       50 Mon Feb  6 17:58:57 IST 2012
>       50 Mon Feb  6 17:58:58 IST 2012
>       49 Mon Feb  6 17:58:59 IST 2012
>       51 Mon Feb  6 17:59:00 IST 2012
>       49 Mon Feb  6 17:59:01 IST 2012
>       51 Mon Feb  6 17:59:02 IST 2012
>
> #
>
> As you can see the version 1.5.24-2 executes date command
> approximately 15-16 times more than in version 1.7.7-1.
>
> The above test is done on MS Windows XP Professional version 2002 SP3, v.5857.
> i7-2620M CPU @ 2.70GHz, 3.16 GB of RAM. Care has been taken to perform
> the above 2 tests one at a time under the same load average on the
> machine.
>
> Is this performance degradation a known issue and does anyone knows if
> this is already addressed in any Cygwin version higher than 1.7.7-1?
>
> Thanks,
> Jaswinder

Dear Jaswinder,
your math looks strange

50/65 = 77 %  so you are losing as performance 23% not 15 times

For 15 times you should have 4-5 instead of 50 as result.

Try last 1.7.10 and see if yo have any change.

Regards
Marco

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