[extropy-chat] Optimal computer configurations [Was: Commentary: Does Karl Schroeder's opinion reallymatter?]

Samantha Atkins sjatkins at mac.com
Mon May 1 18:15:30 UTC 2006


On Apr 29, 2006, at 5:26 AM, Robert Bradbury wrote:

>
> I keep reading about Firefox memory problems, but I live all day in
> Firefox with 7 or 8 open tabs and have never had any problems (Linux
> or Windows).  But I avoid heavy video or multimedia web use, so that
> might be the clue.
>
> How much memory is on your machine and how long do you keep FF  
> running?  You probably will not see them unless you have a machine  
> with 512MB or less and leave the browser running for days.  The  
> problem is basically heap fragmentation interacting with Linux page  
> management.  Over time you have small memory memory allocations  
> (history records, bookmarks, "active" aspects of extensions (RSS  
> records), gmail pages, etc. grabbing small chunks of memory across  
> the entire heap.  The heap size grows over time until the Firefox  
> resident page set is pushing about 70% of the memory on the machine  
> (~350+MB out of 512MB).  That would be manageable if it weren't for  
> the fact that new memory allocations, freeing old memory and the  
> garbage collector that runs at random intervals (I think the GC is  
> in there to support Java & Javascript but I'm not sure) have to go  
> through essentially all of the memory in the heap (all of the  
> allocated chunks are in linked lists).  Even though Linux will run  
> up to 2000-3500 swap-ins per second it still takes a long time to  
> run through all of the pages in the heap that have been paged out.   
> Though it doesn't crash Linux it will make both FF and everything  
> else relatively unusable.  Alternatively it can cause the dreaded  
> "oom-killer" to run which will start killing off processes (Firefox  
> included) until it has enough memory to continue operating.  [In my  
> case it usually takes out Azureus which is a process pig because it  
> needs one for each "peer" it is exchanging files with and a memory  
> pig because it is written in Java and has a poor one-to-many  
> communications design -- but thats a different discussion.] [1]
>

Ah.  Does Firefox have its on memory management internally or does it  
just depend on raw request to the platform alloc routines that it  
then chains together.  From the description i would guess the  
latter.  Is anyone working on it getting larger contiguous chunks and  
sub-allocating and managing those internally?  This sort of thing  
used to be standard practice back in the days of much more limited  
memory.  It isn't that difficult to do.   If I had some free time I  
would be tempted to volunteer to do it myself is no one else is.

Firefox has some other nasty little quirks on OS X.  If you hold down  
the left mouse button instead of just clicking the CPU goes up to  
over 90%!   I get a fair number of crashers with the latest release.   
Often other windows/tabs are frozen while one slow loading page is  
being loaded.  Sometimes what should be a text select ends up acting  
like a right click using my track pad substitute mouse.  This never  
happens in Safari or Opera so it isn't apparently an OS/device  
interaction.

- samantha




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