Back to the (i386) bottle

In the spring of my last year at Washington State University, I bought an eMachines M6807, one of the first reasonably-priced laptops with a 64-bit processor in it. I almost immediately installed a 64-bit distribution on it, and then almost immediately went back to 32-bit (if I remember correctly, it had a Broadcom wifi card that could only be used with 32-bit ndiswrapper).

Somewhere around the time the b43 driver came out, I switched back to 64-bit Fedora and, in the two laptops since then, have stuck with it. Until today. When I upgraded from Fedora 13 to Fedora 14, I started running into memory problems, and it finally came to a head today when Firefox, Evolution and Eclipse combined were enough to make my laptop start swapping. Heavily. The hard drive light may be pretty, but watching the desktop sitting unresponsive isn’t my idea of fun (or of being productive).

I have 3GB of RAM on this laptop. There should be little need for swap, and no thrashing at all. I decided to install Fedora 14 i386 on a second partition and see if it made any difference. Sure enough, with Firefox, Evolution and Eclipse open for several hours, I’m currently sitting at 815MB used, 2185MB free.

So where do I even start filing a bug on this?


Björn Ruberg
Friday, Dec 10, 2010

Yeah, I’m experiencing too that the memory usage of 64-bit Fedora is very very high. It’s annoying. 2 Gigabytes of RAM were not enough - 4 Gigabytes are. At least most of the time.

Colin Walters
Friday, Dec 10, 2010

Basicalyl, you should only install with x86_64 if you need to, i.e. you have 4G of RAM or bigger.

Jonathan Dieter
Friday, Dec 10, 2010

Yeah, I think I’m pretty convinced.

Adam Williamson
Saturday, Dec 11, 2010

Broadly speaking, you don’t. 64-bit code uses more RAM than 32-bit. The difference shouldn’t be that big, though; are you sure you ran Firefox and Evo as long 32-bit as you did 64-bit? They tend to just keep creeping up over time.

The difference should be about a third (more RAM used by 64-bit), I’m told by those smarter than myself.

Keiran "Affix" Smith
Saturday, Dec 11, 2010

Alot of people seem to be having this issue as I have seen. Personally 2GB of RAM and 3.06GHz 64bit Dual Core Processor is quite sufficient for me.

However when I am compiling large things I experience heavy swapping. But that is to be expected really. If you decide to go back to 64-bit at any time try flushing your ram on a set time period and see if that helps.

Jonathan Dieter
Saturday, Dec 11, 2010

There does seem to be a memory leak, but it’s in mutter, or, more likely, the video driver itself (intel). The thing is, even after leaving it running overnight, I still had just under 2GB free and after a killall -9 mutter, was back at 2.2GB free. Under x86_64, after leaving it running overnight, I would have 600MB free and it would have already started swapping. Killall -9 mutter would bring it back to 1.2GB free.

I’ve heard the same 30% more RAM for x86_64, but I’m consistently seeing something more like 100% more RAM for x86_64. I have no idea why and, while I’d like to run x86_64, it’s just not worth that much RAM.

Saturday, Dec 11, 2010

I’m seeing the same thing, I certainly never saw this in Fedora 13. Both x64. I use primarily evolution and firefox. One thing I have noticed is that the IOwait is horrific. Some of that is the swaping but according to iotop not all of it.