Le 07/12/2016 à 11:32, Tommaso Cucinotta a écrit :
On 06/12/2016 23:48, Scott Kostyshak wrote:
On Tue, Dec 06, 2016 at 11:12:56PM +0100, Tommaso Cucinotta wrote:
Hi there,
I haven't seen this, and I use LyX 2.2 on Ubuntu daily. Which Qt version
are you using?
tommaso@tommylap:~$ ldd `which lyx` | grep -i qt
libQtGui.so.4 => /usr/lib/x86_64-linux-gnu/libQtGui.so.4
(0x00007fb5a7544000)
libQtCore.so.4 => /usr/lib/x86_64-linux-gnu/libQtCore.so.4
(0x00007fb5a7052000)
Also, forgot to mention that in the recompiled from master I don't see
the slowness,
but that's recompiled with Qt5.
There is a known slowness problem in 2.2 and master that is due to our
strong reliance on QTextLayout. In Qt4 this is expensive. In Qt5 the
situaiton is better because there is some QTextLayout caching in place.
I have a patch to implement some caching that really improves the
situation in Qt4. However, there are several unresolved things:
- what is the memory overhead?
- should we cache with Qt5 too (I guess not)
- why is the slowness visible on Ubuntu 16.10 (Qt 4.8.7) but not Ubuntu
12.04 (Qt 4.8.1)?
- there are still a few quirks that I did not take time to chase
And of course, the patch has to be adapted to the recent code changes.
I'll post a new version to try soon.
JMarc
