Linked by Thom Holwerda on Mon 23rd Apr 2012 16:29 UTC
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.
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Member since:2007-07-27
I'm quite sure that the memory manager of OSX wasn't derived from BSD, but from Mach. Actually, FreeBSD has adapted that memory manager, so it's rather the other way around. But Apple might learn from the way FreeBSD does things. If it is feasible, as the kernel is quite different.
Member since:2006-01-25
I'm quite sure that the memory manager of OSX wasn't derived from BSD, but from Mach. Actually, FreeBSD has adapted that memory manager, so it's rather the other way around.
That was ages ago... FreeBSD inherited its Virtual Memory Management system from the original Berkeley codebase, which itself was modeled after the Mach VMM - but that was back in the 80s.
Afaik the two codebases haven't seen each other for nearly 30 years. At this point I would say they are probably still architecturally similar but completely different when it comes to the nuts and bolts of how they are implemented. Mach has stagnated for the last 20 years or so - BSD has not.
Member since:2006-01-25
Has anyone checked out the BSD bug reports. The BSD guys are pretty good, so if this was broken when Apple forked Darwin from it, I am sure the BSD guys have fixed it by now. If Apple broke it after they got it, this proves that they shouldn't be mucking about with the internals, but instead, just grab a fresh copy of BSD and lay their UI on top of it again.
Darwin is basically OSX minus the GUI (kernel + userland). Darwin is not a fork of BSD - the parts of Darwin using BSD derived code were ported from FreeBSD.
The XNU kernel is not and never was based on the BSD kernel - it is a heavily modified Mach 3 kernel as was used in NextStep. There were some things done to the kernel to make it mesh better with a BSD userland, but it is still Mach under the hood.
In short there is quite a lot of BSD derived code in OSX, but very very little of it has anything to do with memory management - that is all done by Mach.
Features
Linked by Thom Holwerda on 05/18/13 21:33 UTC
Why does Google get so much credit in the technology industry? Why, despite the company's many obvious failings, do many geeks and enthusiasts still hold a somewhat positive view on the all-knowing technology giant? A specific talk at Google I/O this week provides the answer.
Linked by David Adams on 05/16/13 4:23 UTC
OSNews is a sponsor of this year's O'Reilly OSCON in Portland, Oregon, USA. A lucky OSNews reader will win a free three-day pass, including two tutorials days. To win the pass, post a comment on this story saying something about Open Source Software or OSCON. We'll pick a winner at random next week. If you don't have an OSNews account, you may email us your entry. Part of the conference is the 9th annual Open Source Awards, and today the 16th is the deadline for nominations. If you'd like to nominate an outstanding open source contributor, do it here. Read on for more information about OSCON. Update: The 20% discount code for OSNews readers is "OSN."
Linked by Thom Holwerda on 05/11/13 21:41 UTC
"Windows is indeed slower than other operating systems in many scenarios, and the gap is worsening." That's one way to start an insider explanation of why Windows' performance isn't up to snuff. Written by someone who actually contributes code to the Windows NT kernel, the comment on Hacker News, later deleted but reposted with permission on Marc Bevand's blog, paints a very dreary picture of the state of Windows development. The root issue? Think of how Linux is developed, and you'll know the answer.
Linked by Thom Holwerda on 05/08/13 14:22 UTC
This is one of those news items that's fun to write, fun to read, fun to comment on, and where no one will be able to say anything unkind. It's all just one big ball of awesome fluffiness. TuneTracker, the BeOS radio automation software, has just released something very special: TuneTracker System 5, the first version designed entirely and specifically for Haiku. In fact, it actually includes Haiku in the software package. Better yet, TuneTracker also unveiled several system-in-a-box products - which have Haiku and TuneTracker pre-installed.
Linked by Thom Holwerda on 05/02/13 15:28 UTC
Exactly twenty years ago, a document was published that played a huge role in establishing the web as we know it today. Twenty years later, and this simple and straightforward document is proof of an irrefutable fact: while closed technologies can change markets, open technologies can change the world.
Linked by Thom Holwerda on 04/29/13 21:06 UTC
Oh multitasking. That staple of computing that got thrown out the window with many modern smartphones. We got some rudimentary thing in its place - but even as multitasking on phone and tablets improves, its user-visible side remains cumbersome. Windows 8 has a neat implementation, and now it's time Android follows in it footsteps.
Linked by Thom Holwerda on 04/24/13 22:24 UTC
They're here! Whether that excites you or not remains to be seen, but the Galaxy S4, which will most likely become the best selling Android smartphone of the year by a huge margin, has been reviewed by all the major sites, and there's lots of interesting conclusions in there - although I think most of you will get the gist.
Linked by Thom Holwerda on 04/18/13 11:21 UTC
Nokia has posted its quarterly results for the first quarter of 2013, and just like the quarters that came before, there's not a whole lot of good news in there. The rise in Lumia sales still can't even dream of making up for the sales drop in Symbian phones, and when broken down in versions, the sales figures for Windows Phone 8 Lumias in particular are very disappointing. In North America, Nokia is getting slaughtered.
Linked by Thom Holwerda on 04/16/13 9:29 UTC
The day has finally come: Google has started shipping Google Glass to the lucky few early adopters. Now that it's shipping, Google has also unveiled a lot more about the API and the specifications of the device itself. While the company had already given out substantial details at earlier occasions, there are still a few surprises here.
Linked by Thom Holwerda on 04/15/13 22:44 UTC
Almost exactly three years ago, I wrote about why OSNews was no longer OSNews: the alternative operating system scene had died, and OSNews, too, had to go with the times and move towards reporting on a new wave of operating systems - mobile, and all the repercussions that the explosion of smartphones and tablets have caused. Still, I was wondering something today: why aren't we seeing alternative operating systems on mobile?More Features »
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Member since:
2006-04-10
Has anyone checked out the BSD bug reports. The BSD guys are pretty good, so if this was broken when Apple forked Darwin from it, I am sure the BSD guys have fixed it by now. If Apple broke it after they got it, this proves that they shouldn't be mucking about with the internals, but instead, just grab a fresh copy of BSD and lay their UI on top of it again.