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Re: [kde-linux] How to Get the Combination of NTFS-3g and Konqueror (as a file manager) to consume less CPU




Shlomi Fish posted on Mon, 17 Sep 2012 22:21:58 +0300 as excerpted:


> Replying to myself, I'd like to ask whether anyone can help with this
> issue? Are any KDE dolphin/konqueror developers subscribed to this
> mailing list? Should I ask elsewhere?
> 
> One note is that I noticed it also happens when I browse the ntfs-3g
> partition using Dolphin. It does not happen with GNOME's Nautilus, but I
> naturally prefer Konqueror. It may be because Konqueror and Dolphin keep
> rescanning the directory which inflicts the load on ntfs-3g, but I don't
> know for sure.

This is total speculation as far as ntfs-3g, as I don't run any 
servantware and thus no MS, so thus no ntfs here, at all.  But I do track 
the live-git kernel and routinely report and bisect bugs (including two 
in the current 3.6 kernel development cycle, alone), so I guess I 
probably know more about kernel and filesystem stuff than most users, and 
many admins, simply due to osmosis-absorption of the information I work 
with and read about all the time.

I believe you're correct on the rescans.  Native Linux kernel filesystems 
have various kernel-based notification mechanisms (inotify/dnotify/
fanotify...), such that an app can request notification if a watched 
directory or file changes or is accessed.  Further, I know that kde seems 
to have a gam_server process associated with it (possibly due to the fact 
that I have kde configured to keep a konqueror instance loaded), and that 
gam_server uses fa_notify.  I'd guess that either ntfs-3g's userspace 
nature, or its non-unix-native nature (if not both), block the standard 
use of that mechanism, such that it falls back to a polling loop that 
constantly checks for changes.  Of course that would trigger similarly 
constant ntfs-3g activity, and there you are.

Also note that konqueror/dolphin will load file information for every 
file in a dir, in ordered to be able to display the appropriate icon.  
This can take quite some time and a lot of filesystem access in large dirs 
with thousands of files.  It'll take even *MORE* time (and file accesses) 
if you have previews enabled, particularly for image and video files, for 
which it'll create thumbnails.  Creating the thumbnails the first time 
really DOES take quite some time, such that on big dirs it likely won't 
get done the first time you browse the dir.  Once the thumbnails are 
created and stored, when you revisit the dir, it'll do a quick hash of 
the files and lookup the thumbnail matching the hash, so it doesn't take 
as long, but it still takes more time to hash a file and check for a 
thumbnail that matches, than it does for non-image/non-video files, and 
even on a native POSIX filesystem such as ext2/3/4 or the reiserfs I use, 
it's definitely noticeable.  On a userspace filesystem that's non-native-
POSIX as well, chances are that's going to be less efficient and 
therefore slower.

I don't believe it's possible to tell konqueror/dolphin not to do the 
icon thing, but you CAN turn preview off, thus eliminate the thumbnail 
processing.

FWIW, the icon processing time is one of the big reasons I split my file-
management chores in half, using the "semi-gui" mc (aka midnight 
commander) for sysadmin-type chores, text-file-editing, etc, and only 
using konqueror/dolphin/gwenview for user-type chores, mostly working 
with images and video, where seeing the thumbnails is useful, but also 
one-off file management, where it's easier to open dolphin/konqueror to 
browse a particular dir, than it is to open konsole, then mc, and browse 
the same dir. But except for my home dir and a couple "working" dirs, 
plus the whole images/video tree of course, mc in the konsole CLI is 
nearly always easier and faster.  Use what you want, of course, I'm not 
telling you you have to do it my way.  I'm simply stating what I have 
found works best for me.

And AFAIK, it's not possible to turn off the change-detection stuff 
either, at least thru the normal GUI config.  It's quite possible there's 
a sysadmin level option available, via direct text-based-configfile edit, 
however.  I'd suggest checking the sysadmin documentation at kde techbase, 
if you're interested in pursuing it that far.  (I've read and use the 
info there on kde and xdg hierarchies and environmental vars enough to be 
reasonably familiar with it.  But I've not spent enough time on the rest 
of it to even be sure what subjects are covered, thus I really don't know 
if there's anything of thread-context interest there or not, but that's 
where I'd start looking if I needed the info, here.)

http://techbase.kde.org/KDE_System_Administration

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

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