public inbox for cygwin@cygwin.com
 help / color / mirror / Atom feed
From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: Performance of "ls -F"
Date: Sat, 23 Jan 2016 19:55:00 -0000	[thread overview]
Message-ID: <20160123173552.GE3268@calimero.vinschen.de> (raw)
In-Reply-To: <8737tpqqb6.fsf@Rainer.invalid>

[-- Attachment #1: Type: text/plain, Size: 1497 bytes --]

On Jan 22 22:04, Achim Gratz wrote:
> Corinna Vinschen writes:
> > Just a hint:  ls -F requires to stat every single file.  stat in turn
> > requires to load not only the usual metadata but also to fetch the ACL
> > and convert it to POSIX permissions.
> 
> The timings are from shares mounted with the noacl option, so that bit
> of code shouldn't be involved.  I will try the same operations on an ACL
> enabled mount of the same share later and I also need to find a share
> that is exported from a true NTFS server for comparison.
> 
> > Assuming this slow access only occurs under 2.4.0,
> 
> No, the behaviour is quite a bit older, although I didn't time it since
> I didn't recognize the connection to the aliased ls.  In any case, it
> really is just the determination of whether or not the file is
> executable that takes up all that time.

In the noacl case, Cygwin tries to find out if files are scripts.  It
opens the file and checks the first two bytes in the file for a shebang
(and other stuff).  This may take a lot of time, more so on network
drives.  Can you try adding the "notexec" mount option to the "noacl"
share and see if that helps?

This test is done for a looong time to accommodate FAT filesystems in
the first place.  It might be prudent to disable it by default these
days...


Corinna

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

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

  reply	other threads:[~2016-01-23 17:35 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-21 18:10 Achim Gratz
2016-01-21 18:34 ` William M. (Mike) Miller
2016-01-21 19:09   ` Achim Gratz
2016-01-21 19:56   ` Bill Smith
2016-01-22 15:09     ` Achim Gratz
2016-01-22 22:19       ` Corinna Vinschen
2016-01-22 23:21         ` Achim Gratz
2016-01-23 19:55           ` Corinna Vinschen [this message]
2016-01-25 20:54             ` Achim Gratz
2016-01-25 21:03               ` Corinna Vinschen
2016-01-21 19:54 ` Bill Smith
2016-01-21 21:40   ` Achim Gratz
2016-01-25 20:08 Lemke, Michael  ST/HZA-ZIC2

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160123173552.GE3268@calimero.vinschen.de \
    --to=corinna-cygwin@cygwin.com \
    --cc=cygwin@cygwin.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).