Agitated Climax

I use conky to display a variety of system monitor output on my desktop.  I recently started to use some compositing effects with my window manager, Openbox, and realized that I was seeing quite a bit of flicker when conky updated.  On the conky website there is a faq entry about flickering, that reads:

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Q: Conky won’t stop flickering

A: Conky is designed to draw to the root desktop window. However, there are several other applications which like drawing to the root desktop window. Because of this, Conky has two options available to get around this problem:

• You can try enabling double-buffer. Conky’s double-buffer option uses the X double-buffer extension to provide a flicker-free Conky. This can be done by running Conky with the ‘-b’ parameter, or adding this to your conkyrc: double_buffer yes
• Conky can run in windowed mode, meaning that instead of drawing the the root window it draws to it’s own window. You can move this window around and resize it by right-clicking or left-clicking on the window while holding down the Alt key. This can be accomplished by running Conky with the ‘-o’ parameter, or by adding the following to your conkyrc: own_window yes

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I already had these settings as suggested, but I still occasionally saw flickering.

One of my system monitor scripts outputs a leaderboard of mail statistics from my mail server, and some of the lines can be quite long (especially a list of top relays which can include the “may be forged” string from sendmail’s logs).  When the length of these lines changes, conky has to resize its window, and this is what causes the flickering.  So I calculated the maximum height and width of my output window and added this to my .conkyrc:

minimum_size 1000 1000

Now the flickering has gone completely.

It is worth noting that I don’t think this was caused by the compositing, only that it became more obvious because of the slightly increased update time for a window resize event.

Tags: compositing, conky, flicker, openbox, xcompmgr

This entry was posted on Thursday, June 5th, 2008 at 09:04:08 and is filed under Linux. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.