On Feb 28 03:12, Andrey Repin wrote:
> Greetings, Corinna Vinschen!
> > While we're at it, I just had this weird idea.
> 
> > What if, as soon as the first Cygwin process in a process tree starts,
> > this process not only caches the primary group info, but also caches all
> > supplementary groups from the user's token?  This would slow down
> > startup of the first process slightly, but it would speed up any
> > subsequent request for group information of a group in the user's token.
> > An `id' call would be almost instant, and `ls' calls would probably be
> > faster as well.
> 
> Umhm. I'd have to see, how slightly. Because my primary use of Cygwin tools
> does not expect to have a parent Cygwin process. (I.e. diff'ing between
> file manager panels.)
> 
> > As always, there's a trade-off: Users running cygwin processes from CMD
> > a lot would encounter a slowdown.
> 
> > What do you think, guys?
> 
> Needs some tests. I would certainly appreciate faster initial startups, but if
> the delay is manageable, I can cope with more long-term friendly approach.
> I've got entangled in current work and lost track of snapshots for now.
> If there's some DEF's in library, that I can toggle and rebuild it with certain
> features enabled and disable for local test, I'd be glad to have a round at it
> over weekend.

I've just uploaded a new snapshot to http://cygwin.com/snapshots/

It allows you to do the following in /etc/nsswitch.conf:

  db_cache: no

    No caching of passwd and group data at all

  db_cache: yes

      Caching of passwd and group data, no initial caching of the user's
      supplementary groups from the user token.

  db_cache: full

      This is the default now.

      Caching of passwd and group data *plus* initial caching of all groups
      from the user token.

Please try it out.  Average timings from your environment (process
startup, and calling `id') would be nice.


Thanks,
Corinna

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