Mailing-List: contact cygwin-developers-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-developers-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin-developers/>
List-Post: <mailto:cygwin-developers AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-developers-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-developers-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin-developers AT sources DOT redhat DOT com
Date: Sun, 10 Jun 2001 20:17:50 -0400
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin-developers AT cygwin DOT com
Subject: Recent changes to path_conv::check -- ouch
Message-ID: <20010610201750.A8503@redhat.com>
Reply-To: cygwin-developers AT cygwin DOT com
Mail-Followup-To: cygwin-developers AT cygwin DOT com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.3.11i

Egor,
I guess I missed this before but you added a potentially expensive
operation to the middle of the path_conv check loop by calling
update_fs_info repeatedly.  This looks like we will suffer a performance
hit in the non-ntea case for the privilege of a performance gain for the
use of ntea for symlinks.  I don't think that's acceptable.

It also looks like even in the ideal case, we're guaranteed to call
update_fs_info twice on the same path.

Also, you seemed to have changed the name of some recently added
elements to the path_conv class.  vol_flags became fs_flags and
vol_serial became fs_serial.

path_conv is probably the most frequently called function in cygwin so
we've tried very hard to keep the code flow as optimized as possible by
not calling the OS too often.  Maybe I'm wrong, but I think you've
probably added a performance hit with your recent changes.

Have you run any before/after performance checks on your code?

cgf