Bug 104721

Summary:	kmail freezes while messages are moved to another dir
Product:	[Unmaintained] kmail	Reporter:	Gioele Barabucci <dev>
Component:	general	Assignee:	kdepim bugs <kdepim-bugs>
Status:	RESOLVED UNMAINTAINED
Severity:	normal
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Gioele Barabucci 2005-04-28 19:01:18 UTC

Version:            (using KDE KDE 3.4.0)
Installed from:    Gentoo Packages

Kmail GUI freezes for a long time when you select many messages from a folder and moves them to another, but only if one of the folders is in mbox format.

maildir <-> maildir moves are quite fast so the GUI blocks anyway but just for less time.

It took 2+ hours to move 3000 messages from mbox to maildir.

You should remove the GUI freeze and make possible to stop the process.

Comment 1 Gioele Barabucci 2005-04-28 19:02:31 UTC

The move is very slow even if both dirs are fully contained in ram (no disk activity).

Comment 2 Ivan S. J. 2007-07-15 15:20:16 UTC

(KDE 3.5.1, KMAIl 1.9.1)

maildir<->maildir move is not that fast either.

Moving 6309 messages between 2 NFS maildirs took several minutes and consumed considerable network bandwidth:

Before:
# ip -s link show dev lan1
2: lan1: <BROADCAST,MULTICAST,UP> mtu 6000 qdisc pfifo_fast qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    272590096  213635   0       0       0       1      
    TX: bytes  packets  errors  dropped carrier collsns 
    210820280  213657   0       0       0       0      
After:
# ip -s link show dev lan1
2: lan1: <BROADCAST,MULTICAST,UP> mtu 6000 qdisc pfifo_fast qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    450667222  392535   0       0       0       1      
    TX: bytes  packets  errors  dropped carrier collsns 
    363576848  392555   0       0       0       0      

178MB read, 152MB write.
Since message can be moved between maildirs on the same device with a simple rename, this is inefficient.

For comparison:
A simple 'mv' of 6309 files took 20 seconds,
# ip -s link show dev lan1
2: lan1: <BROADCAST,MULTICAST,UP> mtu 6000 qdisc pfifo_fast qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    459172546  419878   0       0       0       1      
    TX: bytes  packets  errors  dropped carrier collsns 
    372514124  419896   0       0       0       0      
isjsys:~ # ip -s link show dev lan1
2: lan1: <BROADCAST,MULTICAST,UP> mtu 6000 qdisc pfifo_fast qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    465899264  451431   0       0       0       1      
    TX: bytes  packets  errors  dropped carrier collsns 
    377347846  451449   0       0       0       0      

= 6MB read, 5MB write

(Yes, I know that KMail needs to update the index too, but still...)

Comment 3 Laurent Montel 2015-04-12 09:46:27 UTC

Thank you for taking the time to file a bug report.

KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2.

We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.