Re: 1.5.20-1: ls -F slowness

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Nov 15 14:34, Scott Roland wrote:
> I tracked down my problems with an ls -F on a network share taking a
> very long time.
> 
> If I use cygwin version 1.5.19-4 from the time machine:
>   ftp://www.fruitbat.org/pub/cygwin/circa/2006/06/11/081007
> then an ls -F operation takes a couple of seconds.
> 
> If I then upgrade to version 1.5.20-1 from the time machine:
>   ftp://www.fruitbat.org/pub/cygwin/circa/2006/07/02/093005
> cygwin is the only package that gets updated, but now the same operation
> takes a couple of minutes (over 100 times slower).
> 
> The slow ls -F also occurs with the latest release. A vanilla ls does
> not take a long time.
> 
> I have attached a couple of lines from an strace of the ls -F on the
> 1.5.19-4 and 1.5.20-1 versions. There are a couple of differences in the
> strace, but the slowdown can be seen on the following step, which takes
> over 700 times as long:
>   fhandler_base::set_flags: flags 0x110000, supplied_bin 0x10000
> 
> Does anyone have any insight on why things got dramatically slower with
> version 1.5.20-1?

I looked through this and I'm just puzzled.  I'd expect 1.5.22 to be as
quick as 1.5.19 with respect to opening files on a share.  And it is in
my tests.  The number of usecs above is the time it takes to convert an
ASCII filename to a UNICODE filename, setting a couple of flags and then
call NtCreateFile.  There are no changes in that code between 1.5.19 and
1.5.20 which would in any way explain the slowness you see.  In my local
tests it's always roughly about 1000 usecs.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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