Why, when brought out of sleep, are our Macs unusably slow when Safari was left running before they went into sleep mode?

May 12, 2011 3:02 PM

Why, when brought out of sleep, are our Macs unusably slow when Safari was left running before they went into sleep mode?

I help manage the computer labs at my college. The absolute bane of my existence right now seems to be Safari--the browser of choice for most of the students using our Macs.

When Safari is left open on an iMac and said iMac goes to sleep it will, upon being awoken, be almost unusable from total slow down. It take several minutes for me to just bring up the force quit prompt to shut Safari down, and it's almost always the only program running with the "not responding" text next to it. It's so slow that it's generally quicker just to cut power to the computer and restart it.

This isn't an issue with any of the other browsers, which kinda nullifies my theory that it has something to do with Flash. Please, does anyone have any ideas?

posted by pandemic to technology (11 answers total)

At the risk of being a wet blanket, there's not enough information here to tell you much. It would be helpful if you could reproduce the problem and do two things:

sudo spindump
sudo fs_usage -w

Let the second one run for ten seconds or so, then hit control-c to stop it.

When you've captured that, show it to us somehow. (It's going to be a lot of data, so you won't be able to add it here as a comment. Pastebin, host it somewhere, send it to one of us, etc.)
posted by Mikey-San at 3:17 PM on May 12, 2011

(Telling us a little about the system, as well, would be good. OS version(s), amount of RAM in the machines, startup disk size and available space, etc.)
posted by Mikey-San at 3:18 PM on May 12, 2011

Right, I wrote the question in haste and failed to give much of anything in details:

The iMacs are running Snow Leopard 10.6.6. 2 Gigs of RAM, 2GHz Core 2 duo. I'll be by the computer labs in a bit so I'll post more details a little later on.
posted by pandemic at 3:25 PM on May 12, 2011

On my machines (10.6.7, 4 Gigs, Core 2 duos), Safari tends to have a runaway cache which totally fills RAM and then ends up paging out to virtual memory. Then things start getting really slow.

This happens even after light web browsing. It seems to happen more aggressively to my mini (3,1) than my iMac (7,1).

I find it highly annoying.
posted by Homemade Interossiter at 3:39 PM on May 12, 2011 [1 favorite]

Safari will quickly eat 2GB of ram, especially if flash is installed.
posted by mmdei at 4:00 PM on May 12, 2011 [1 favorite]

It would be good also to see:

top -l 2
posted by Mikey-San at 5:25 PM on May 12, 2011

Easy solution: If you're managing preferences (and in a lab, you really really really really should), you could allow users to run Chrome and/or Firefox and disallow Safari.
posted by Oktober at 5:32 PM on May 12, 2011

We allow Safari as well as Chrome and Firefox. Most people just choose Safari.
posted by pandemic at 8:36 PM on May 12, 2011

I have a very similar setup and have not experienced this. Could possibly be the effect of ClickToFlash, a sweet little flash blocker. Any flash content on a page will be replaced by a transparent box. You can click on any individual flash object to enable it for that session only.
posted by Aquaman at 10:15 PM on May 12, 2011

ClickToFlash saves my sanity, but I suspect it wouldn't go over well with unsuspecting users in a lab. RAM is cheap, but I understand budget processes can be a pain.
posted by mmdei at 11:08 PM on May 12, 2011

Are user home folders being directed towards the server or saved locally? I've seen major issues with Mac networks when home folders are redirected directly to the server and bypassing local storage altogether. We have a couple hundred laptops (all with network accounts whose home folders are on the local machine and then synced back to the server) running 10.6.4 and haven't seen this issue at all.

If you doing any kind of file sharing with a Mac server, I'd check to see if that's your chokepoint. Mac servers going crazy do weird things to clients.
posted by jmd82 at 11:11 AM on May 13, 2011