[Okular-devel] [Bug 177213] High X server memory consumption

[Oscar Fuentes]

https://bugs.kde.org/show_bug.cgi?id=177213





--- Comment #29 from Oscar Fuentes <ofv wanadoo es>  2010-03-17 19:45:25 ---
(In reply to comment #26)
> #25 to me it's fairly obvious, each time you allocate a X pixmap in the server
> side you get a handle in your process, if you don't free the local handle there
> is a local leak, if you do not leak it, it means you freed the X pixmap too.
> 
> But as it seems you have a better idea i'm open to your suggestions.
> 
> And well, if the bug is about okular allocating X memory we can close it
> altogether because that is not a bug at all.

This was discussed on the past. The X server (all X servers I know) are not so
smart managing resources that they can cope with the usage pattern okular does.
Even if okular frees all handles, the X server sometimes does not give back to
the OS all the allocated memory, and then fragmentation can prevent reusing
that memory on another okular session. This is not a problem with most X
applications, because the amount of allocated X resources is low (compared with
okular).

As mentioned on the past too, I did some informal benchmarks and perceived no
speed difference on page rendering after changing Okular's memory usage
setting, nor I perceive differences with other pdf viewers (xpdf, for
instance). What I observe is performance degradation when X ends having
gigabytes of allocated memory after heavy use of okular with the "normal"
memory usage setting. This is a critical issue when the X server is a machine
wiht 1 GB of RAM and the X client has 8 GB: after browsing a few hundred pages
the X server starts paginating and finally crashes due to lack of memory.

So, it is not a bug on okular itself, but a QoI (quality of implementation)
issue. The X server is not as smart is we would like it to be; okular is
abusing the X server when it allocates hundreds of MBs of pixmaps; sometimes
this usage pattern ends on serious performance degradation or crashes.

So, why don't you set the default setting to "low memory usage"? You claimed on
the past that the current setting was chosen due to the performance improvement
that it provides. My experience shows that there is no such improvement.
Perhaps you can show a case that justifies the huge memory usage?

-- 
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.