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| 'Something is deeply broken in OS X memory management' |
| By Thom Holwerda on 2012-04-23 16:29:22 |
| Adam Fields and Perry Metzger have been investigating the serious performance issues people are experiencing with Lion. "Frequent beachballs, general overall slowness and poor UI responsivness, specific and drastic slowdowns on every Time Machine run, high memory utilization in Safari Web Content, mds, and kernel_task processes, large numbers of page outs even with a good deal of available RAM, and high amounts of RAM marked as inactive which is not readily freed back to other applications, with page outs favored." Apparently the issue is that the "virtual memory manager is bad at managing which pages should be freed from the inactive state and which ones should be paged out to disk". I won't make myself popular with a certain part of our readership, but really, is this considered a new problem? Mac OS X has always had terrible memory management, and where Windows has continuously become better at it, Mac OS X seems to have been stagnant and even getting worse. This is what happens when the company earns 2/3s of its revenue somewhere else. |
|
| My experience |
| By henderson101 on 2012-04-24 09:42:51 |
|
Background: I have a late 2007 Santa Rosa Macbook (the last black plastic one) that dual boots Snow Leopard, Leopard and Windows 7 Pro. I also have one of the base model Mac Mini's with a core i5 that dual boots Lion and Snow Leopard. Experience: Lion, 99% of the time is fine for me. It does have weird slow downs occasionally, but I've never seem really big issues. I hacked a retail install on Snow Leopard to boot on the Mac Mini, and it runs pretty much the same. It boots from USB (so,yeah, the disk performance is poorer), but the general OS is fine. I'd advocate any one who has a similar Mac to give Snow Leopard a go. My Macbook has always been less responsive with Snow Leo, not crazily, but enough to warrant keeping Leopard around. Windows 7 on the same hardware is pretty uninspiring. But do you want to know what really makes a difference? Memory. I have 4GB in both Macs, and it really does make a difference. I'm going to upgrade the Mini to 8GB as soon as I get some spare cash. |
 - Score: 2 |
| opposite issue |
| By stooovie on 2012-04-24 09:57:24 |
| I have the opposite problem - I have plenty of memory (12 GB) that very rarely gets used, 2/3 to 1/2 of RAM is almost always free, yet system swaps everything and caches nothing into RAM. |
| - Score: 2 |
| Same Problem in FreeBSD? |
| By puenktchen on 2012-04-24 15:18:08 |
|
The related implementation in FreeBSD seems to have a similar problem: NetBSD users have also reported that UVM’s im- provements have had a positive effect on their applica- tions. This is most noticeable when physical memory becomes scarce and the VM system must page out data to free up memory. Under BSD VM this type of paging causes the system to become highly unresponsive, while under UVM the system slows while paging but does not become unresponsive. http://static.usenix.org/event/u... Should be easy to fix: just start to page out some stuff in time before there is no memory left. |
| - Score: 2 |
| RE[5]: Software engineering VS coding |
| By Soulbender on 2012-04-25 11:14:16 |
|
> I noticed that Swedes are much better at English than us Frenchmen. Now there's a surprise :P |
| - Score: 2 |
| RE[3]: Editorial? |
| By dsmogor on 2012-04-25 17:31:04 |
|
IOS doesn't use swap, that's the difference. Edited 2012-04-25 17:35 UTC |
| - Score: 3 |
| RE: opposite issue |
| By dsmogor on 2012-04-25 17:36:21 |
| Change the swappiness parameter :) |
| - Score: 2 |
| RE[6]: Software engineering VS coding |
| By Neolander on 2012-04-25 17:49:19 |
|
> Now there's a surprise :P Well, I had to see it first in order to believe it :) |
| - Score: 1 |
| RE: Clean Install |
| By zima on 2012-04-28 14:39:08 |
|
> The key is to do a clean install, never an upgrade. Most of the issues arise from upgrading. Wait, wasn't this supposed to be the problem & requirement of Windows, but not of other operating systems and not of MacOS in particular? |
| - Score: 2 |
| RE[4]: Software engineering VS coding |
| By zima on 2012-04-29 19:30:26 |
|
> This is one of the reasons why most Europeans speak on average 3 languages. The mother language and two foreign languages, one of the being English. I really don't think "most" and "on average" describes it accurately... Looking at http://en.wikipedia.org/wiki/Lis... the EU has 46% for English but that includes UK and Ireland - so, from the numbers given, closer to 33%. Europe is certainly lower. That's for the lingua franca of our times - other languages should have, comparatively, notably lower adoption as a foreign tongue. Personal anecdote time: I'm in one of the late EU member states, a hop across the Oder from your place. While my EN is bearable, my DE is... pathetic, I can't really speak it - basically I can just largely follow German films, if the dialogue isn't too sophisticated. Once, when I wrote an email in German(?), Gmail ad system thought it was Swedish... (makes tiny bit of sense I guess, Swedish supposedly being in some ways "between" DE and EN :P ) And... that still places me among the local minority of people able to communicate quite effectively with foreigners - better than most around me. (weird and too bad with DE, really: my grandfather was mostly German, living with us until his death when I was 6, but for some reason he didn't really transfer to me anything - maybe his ill-health, maybe because instilling in the grandson German language was still perceived as socially inappropriate in the 80s; and I also had more than half a decade of DE in school... OTOH my formal EN education started only when I was 15 - but by then I was already much more fluent in it than I ever was in German ...the luck of getting one good books+cassettes course at the age of 5-6, plus http://en.wikipedia.org/wiki/Voi... plus the "simple" EN of Cartoon Network or C64 games? Later on some TV stations in general, and that's all... And so, when at the age of 14 I was among those who won German language school competition, and on that basis went to Essen on a short student exchange - I communicated mostly in English; most of us did) |
| - Score: 2 |
| RE[5]: Software engineering VS coding |
| By zima on 2012-04-29 19:39:06 |
|
> I noticed that Swedes are much better at English than us Frenchmen. Not knowing Swedish was an annoyance, but not a crippling handicap. Nordic region in general seems to be at the top, close to countries where EN is the "native" language. http://en.wikipedia.org/wiki/Lis... |
| - Score: 2 |
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