May 2013 - Darwin-kernel - lists.apple.com

Re: How can Mountain Lion boot so fast?
by Nick Blievers 20 May '13

20 May '13

On 21/05/2013, at 9:21 AM, Andrew Gallatin wrote: > On 05/20/2013 05:30 PM, Nick Blievers wrote: >> I'm guessing your Retina Display MacBook Pro boots from an SSD. SSD's are insanely good (compared to spinning disks) at random, concurrent access, as happens during boot. Even my Windows system boots pretty quickly these days thanks to the SSD…. and my OSX on a spinning disk is relatively slow to start up. >> >> launchd is also pretty neat, it allows concurrent start up of daemons (is linux start up still controlled via scripts and sequential? Its been a while since I've had anything to do with linux), and also on-demand start up, which pushes > > It depends what "linux" you're talking about. Ubuntu & Fedora use > newfangled launchd-ish things like upstart and systemd, and boot almost > instantly. RHEL still uses traditional SysV init scripts. Ubuntu 12.04 > boots in about 8 seconds (in a VM). The nice thing about Ubuntu is that > they've maintained enough of the SysV init stuff for backwards compat to > be mostly seemless for 3rd party startup scripts. Oh that is cool (totally off-topic, but cool anyway :) ). About time they moved to something smarter (scripts have a certain simplicity in their favour, but doing things sequentially is a bit silly these days!). I remember seeing a start up system based on Make at one point… that was an interesting idea. Cheers Nick _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: How can Mountain Lion boot so fast?
by Andrew Gallatin 20 May '13

20 May '13

On 05/20/2013 05:30 PM, Nick Blievers wrote: > I'm guessing your Retina Display MacBook Pro boots from an SSD. SSD's are insanely good (compared to spinning disks) at random, concurrent access, as happens during boot. Even my Windows system boots pretty quickly these days thanks to the SSD…. and my OSX on a spinning disk is relatively slow to start up. > > launchd is also pretty neat, it allows concurrent start up of daemons (is linux start up still controlled via scripts and sequential? Its been a while since I've had anything to do with linux), and also on-demand start up, which pushes It depends what "linux" you're talking about. Ubuntu & Fedora use newfangled launchd-ish things like upstart and systemd, and boot almost instantly. RHEL still uses traditional SysV init scripts. Ubuntu 12.04 boots in about 8 seconds (in a VM). The nice thing about Ubuntu is that they've maintained enough of the SysV init stuff for backwards compat to be mostly seemless for 3rd party startup scripts. Drew _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: How can Mountain Lion boot so fast?
by Michael Crawford 20 May '13

20 May '13

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Re: How can Mountain Lion boot so fast?
by Nick Blievers 20 May '13

20 May '13

I'm guessing your Retina Display MacBook Pro boots from an SSD. SSD's are insanely good (compared to spinning disks) at random, concurrent access, as happens during boot. Even my Windows system boots pretty quickly these days thanks to the SSD…. and my OSX on a spinning disk is relatively slow to start up. launchd is also pretty neat, it allows concurrent start up of daemons (is linux start up still controlled via scripts and sequential? Its been a while since I've had anything to do with linux), and also on-demand start up, which pushes the startup off until the daemon is required. And, if we are comparing with OSX 10.0, the kernel is much much better. Gone are the days of giant kernel locks. So… its a bit of both. SSDs make a huge difference, and the OS has improved as well. Nick On 21/05/2013, at 7:03 AM, Michael Crawford wrote: > I've been running Mac OS X since 10.0. I even used it on a Power Macintosh 8500, that OS X directly from Apple didn't support, but that would work if you installed some drivers that some developer cooked up for the older hardware. > > OS X ran OK on my 8500, but was so slow as to be unusable. It was a crushing disappointment, as at the time I didn't have the cash for a new box. > > Older releases of Mac OS X showed a progress bar during boot, with messages that reported what step was taking place. > > My 10.8.3 Retina Display MacBook Pro shows the circular progress indicator for five or ten seconds - I think mostly to run a memory test - then the screen changes color, and I'm presented with my password prompt just a second or two later. > > I'm having a hard time figuring out how OS X can boot so fast. It's not just the kernel initialization, there are a lot of demons to start, the display server and so on. > > We have the Kernel Extension cache, but there must be a lot more to it. This speed can't be explained just by the faster CPU. > > Try booting your Mac off of Windows or Linux. There is no comparison. > > Curiously, > > Mike > -- > Michael David Crawford > mdcrawford at gmail dot com > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/darwin-kernel/nblievers%40threatmet… > > This email sent to nblievers(a)threatmetrix.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: How can Mountain Lion boot so fast?
by Athanasios Douitsis 20 May '13

20 May '13

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How can Mountain Lion boot so fast?
by Michael Crawford 20 May '13

20 May '13

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Re: Darwin
by Andrew Gallatin 20 May '13

20 May '13

On 05/20/2013 04:37 PM, Rick Macklem wrote: > Andrew Gallatin wrote: >> Some corrections: >> >> On 05/20/2013 03:23 PM, Michael Crawford wrote: >>> The Darwin kernel is a massive fork of the FreeBSD kernel. Darwin >>> has >>> the Mach microkernel statically linked in - not as a microkernel - >>> to >>> enable >> Although it is a common misconception, the darwin kernel is most >> certainly not a fork of FreeBSD. It is a direct descendant of the NeXT >> kernel, which is a shotgun wedding of BSD and Mach (those were popular >> in the 90s, DEC Tru64 UNIX is another example) and it far pre-dates >> FreeBSD. The similarities between FreeBSD & MacOSX are mainly due to >> common BSD heritage, as well as some code ported between the two >> (kqueue, ipfw). They are more like second or 3rd cousins than >> siblings. >> > Well, if you looked at xnu-592 (or somewhere around there, which is > the open sourced kernel sources related to OS X 10.3 Panther) you > will see a lot of FreeBSD code in it and not just 4.nBSD. > Mac OS X diverged dramatically when Apple did 10.4 Tiger, at least > in the vfs/vop area that I worked in. I would have called the early > 10.n (up to n == 3) closer that 2nd cousin, but I'm just nitting picks. > Yes, up until the KPIs were enforced, things were much more similar. I used to actually maintain a driver for some older HPC stuff where the ethernet driver shared code on MacOSX, FreeBSD and DEC Unix. I had the core C tx / rx routines shared, and the OS-specific wrappers in C++ for OSX. After KPIs, that got a lot harder, but that product died around the same time, so it did not really matter. The network stack from around panther has more FreeBSD CVS references in it than I remembered seeing. But I would not even remotely call it a "fork". They just pulled in fixes & improvements from compatible open source projects. Drew _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: Darwin
by Rick Macklem 20 May '13

20 May '13

Andrew Gallatin wrote: > Some corrections: > > On 05/20/2013 03:23 PM, Michael Crawford wrote: > > The Darwin kernel is a massive fork of the FreeBSD kernel. Darwin > > has > > the Mach microkernel statically linked in - not as a microkernel - > > to > > enable > > Although it is a common misconception, the darwin kernel is most > certainly not a fork of FreeBSD. It is a direct descendant of the NeXT > kernel, which is a shotgun wedding of BSD and Mach (those were popular > in the 90s, DEC Tru64 UNIX is another example) and it far pre-dates > FreeBSD. The similarities between FreeBSD & MacOSX are mainly due to > common BSD heritage, as well as some code ported between the two > (kqueue, ipfw). They are more like second or 3rd cousins than > siblings. > Well, if you looked at xnu-592 (or somewhere around there, which is the open sourced kernel sources related to OS X 10.3 Panther) you will see a lot of FreeBSD code in it and not just 4.nBSD. Mac OS X diverged dramatically when Apple did 10.4 Tiger, at least in the vfs/vop area that I worked in. I would have called the early 10.n (up to n == 3) closer that 2nd cousin, but I'm just nitting picks. rick > > I should have said in my first reply that network drivers are not > > part > > of the I/O Kit. They are written in C and work just like the FreeBSD > > net drivers. > > Having written 10GbE drivers for both OSes, I can say with authority > that this is totally & utterly false. Network device drivers are c++ > in > MacOSX, and C in FreeBSD, and use a totally different driver API > (IOKit > vs FreeBSD's own nameless API). Now, some of the core kernel > structures are similar (ifnet, mbufs) but none are exposed directly to > drivers in MacOSX, and the core things a driver has to do > (configuration, interrupts, transmits, receives) are quite different > between the two OSes. > > Drew > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/darwin-kernel/rmacklem%40uoguelph.ca > > This email sent to rmacklem(a)uoguelph.ca _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: Darwin
by Todd Heberlein 20 May '13

20 May '13

On May 20, 2013, at 11:57 AM, Alexander von Below <below(a)mac.com> wrote: > Amit Singh's "OS X Internals" is really the definite book on the matter. However, it does not really cover the Intel architecture. Something for people to keep their eye out for OS X Internals | Gwynn'e Blog http://blog.darkrainfall.org/2013/01/os-x-internals/ > Yes. As of November 2012, I was contracted by Pearson to author a second edition of Mac OS X Internals, which in keeping with Apple’s change in naming, will now be titled “OS X Internals: A Systems Approach”. > At this time, I have no solid release date to offer. My best guess for a release is late in 2013. Todd _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: Darwin
by Michael Crawford 20 May '13

20 May '13

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