[mythtv-users] Front end memory usage

Michael T. Dean mtdean at thirdcontact.com
Sun Oct 30 17:55:56 EST 2005


Robert Johnston wrote:

>On 30/10/05, Michael T. Dean <mtdean at thirdcontact.com> wrote:
>  
>
>>Alberto Alonso wrote:
>>
>>>I am finding more info on this. It seems to be mostly
>>>related to theme and resolution. Going down to 640x480
>>>I now get 57M of RES usage, which is a heck of a lot
>>>better, but still rather large if you ask me.
>>>
>>>What theme and resolution are you using to the 17M
>>>resident?
>>>
>>>Also, does anybody know of any setting to set things up
>>>that maybe doesn't cache the whole theme stuff to memory?
>>>It seems that reading from disk on a page change should be
>>>fast enough.
>>>
>>I'm using Minimalist-wide (which is appropriate for widescreen TV's).
>>
>>Another Myth box I maintain shows:
>>
>>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>>32076 root      15   0 69764  26m  18m S  6.3  5.3 752:49.75 mythfrontend
>>
>>And the guy who owns it uses visor--the theme with the clouds (a
>>"complex" background image)--at 1024x768.
>>
>>I really don't think it's the theme's being cached that's causing the
>>problem.  The default theme, as distributed (XML descriptions and
>>"unscaled" images), is only 2736KB, Minimalist wide is 2900KB, and visor
>>is 2828KB.  On disk, my themecache (the scaled
>>images)--Minimalist-wide.1920.1080--is 7776KB, and visor.1024.768 is
>>5712KB.  Also, TTBOMK, Myth doesn't maintain the entire theme in
>>memory.  Images are cached on disk as just described.  Also, since it
>>notices changes to the XML theme files at runtime, it may not even keep
>>the theme descriptions in memory (although I haven't looked at the
>>source to verify this--it could also be checking modification times or
>>something).
>>
>>Regardless, I can't see the theme causing it to take 50-100MB of RAM.
>>Maybe for a program like Windows Media Player, but this is MythTV.  ;)
>>    
>>
>Remember that those theme images are stored (on disk) in a compressed
>form. I believe a QImage is the raw bitmap, uncompressed, in memory.
>So a 1024x768x32-bit image would be 3MiB (25165824 bits)
>
OK.  We've got 2.5MiB out of his 56MiB RES/VIRT unknown at 640x480 to 
107MiB RES/171MiB VIRT at some unspecified resolution, so where's the 
rest--especially considering there's probably only one full-size image.

Also, as specified earlier in the thread, my 1920x1080 frontend with a 
simple theme is only using 16MiB RES/57MiB VIRT--significantly less than 
his 640x480 frontend.  And, as shown in the message you quoted, the 
frontend with the 1024x768 complex theme is using 26MiB RES/68MiB VIRT.  
So if the theme is the major problem, both should be using more memory 
than he is...

Mike


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