Lion gets progressively slower over days of uptime -- Any remedies?

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Level 1

20 points

Lion gets progressively slower over days of uptime -- Any remedies?

From Tiger to Snow Leopard, I could have weeks to months of uptime on my Mac without any major issues. But now with Lion, the machine just gets slower and slower and slower over the course of days. What's worse, this is happening on a Core i7 17" MBP with 8GB of RAM, and Snow Leopard ran beautifully on this system. I notice that some things like "Safari Web Process" and "kernel_task" get huge. Safari will take gigabytes (I don't have THAT many web pages open, and I use ClickToPlugin to avoid flash and such), and the kernel will approach a gigabyte. At the time that the system gets slugglish (unusable even), the disk sounds like it's thrashing, but Activity Monitor has never reported less than 1.5GB of RAM free. Since some apps are rather leaky (e.g. Safari), I have tried just quitting all my apps and restarting them, but that doesn't really help all that much. The only way I have found to get performance back is a reboot. It's shameful that I should have to reboot my Mac at least once per week.

I have filed bug reports on a lot of the performance problems, and the devs have actually been responsive, having me run more tests (sysdiagnose, trace, etc.), but they've given no hints about what I could do to mitigate the problems. And that's what I'm asking about here.

Are there settings I should look at pertaining to kernel memory, disk caching, swappiness, etc. that might improve system memory usage?

Are there any programs that will give me a detailed report or map of system memory usage so that I can identify which programs are using what memory and which ones are causing swapping (or whatever the real problem is)?

Are there any more general diagnostic programs (something on top of dtrace, perhaps) that will help me to understand where the performance bottlenecks are?

Any other diagnostic tools that I haven't thought of?

Thanks!

P.S. I think that 10.7.3 has improved some things, but the main effect has been that I can go a little bit longer before having to reboot.

Posted on Feb 10, 2012 6:25 AM

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Answer 1

Linc Davis

Level 10

209,547 points

Feb 10, 2012 7:01 AM in response to theosib

Disconnect all wired peripherals except keyboard, mouse, and monitor, if applicable.

Launch the usual set of applications you use when you notice the slowdown. Then launch the Activity Monitor application by entering the first few letters of its name into a Spotlight search, and select the CPU tab. Select All Processes from the popup menu in the toolbar, if not already selected. Click the heading of the % CPU column in the process table to sort the entries by CPU usage. You may have to click it twice to get the highest value at the top. What is it, and what is the process? Also post the values for % User, % System, and % Idle at the bottom of the window.

Now select the System Memory tab. What values are shown in the bottom part of the window for Page outs and Swap used?

Launch the Console application and select “kernel.log” from the file list. Post the dozen or so most recent messages in the log -- the text, please, not a screenshot. If there are repeats, please post only one example of each repeated message.

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Answer 2

theosib Author

Level 1

20 points

Feb 10, 2012 10:02 AM in response to Linc Davis

Typically when the sluggishness happens, the total CPU load is quite low. The system activity is dominated by access to the root disk. I know that swapping happens, but I haven't quantified it. However, since I typically have over a 1.5GB of free memory in that state, a lot of swapping seems inappropriate. Also, when I quit the apps, there's a lot more free memory, but system performance is still dominated by disk I/O. I typically don't have any wired peripherals, except sometimes external keyboard and mouse; disconnecting those doesn't help. Sometimes I have a bluetooth keyboard, but that doesn't have any effect either. I haven't tried disconnecting the wireless network when this happens, but I do know that there's generally not much network I/O in the sluggish state. Nothing more than usual anyhow. Page loads are slower, but that's because Safari freezes up.

When this happens again, I'll post the rest of the info you requested. I'll take a few days, since I just rebooted this morning.

Thanks!

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Answer 3

etresoft

Level 8

46,176 points

Feb 10, 2012 10:24 AM in response to theosib

I think the biggest problem is that Safari caches everything. Since it is a cache, it technically isn't a leak, but it can behave like it. Another issue is that Lion doesn't seem to play well with some DNS servers. If you are using Safari frequently, it may seem slow just because name lookups are taking so long. I suggest using OpenDNS nameservers instead of those of your ISP.

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Answer 4

theosib Author

Level 1

20 points

Feb 10, 2012 10:50 AM in response to etresoft

I can try OpenDNS, but the fact is, ALL apps get sluggish. Safari may or may not actually be worse. I'm singling it out because of its memory usage. But other apps like Mail, Microsoft Office, iWork, Preview, etc. ALL get slow. The whole system gets slow.

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