July 2009 - Darwin-dev - lists.apple.com

Re: Mac OS X Jails
by Mo McRoberts 30 Jul '09

30 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Thu, Jul 30, 2009 at 16:33, <z3r0_f4ct0r(a)mac.com> wrote: > Is it possible to create Jails in Mac OS X like in FreeBSD or Solaris Zones? > > I haven't found any information on this. Darwin doesn't include the jail() syscall, nor zones, but sandboxing in 10.5+ may let you achieve the same thing (I haven't looked deeply at it)—sandboxing seems to be mostly designed as a more advanced form a chroot(), rather than a way to run a pseudo-virtualised environment (possibly with its own IP or dedicated NIC assigned, along with other selected physical resources). M. -- http://nevali.net _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Mac OS X Jails
by Brian Mastenbrook 30 Jul '09

30 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Jul 30, 2009, at 10:33 AM, z3r0_f4ct0r(a)mac.com wrote: http://www.parallels.com/products/server/mac/ -- Brian Mastenbrook brian(a)mastenbrook.net http://brian.mastenbrook.net/ _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Is it possible to create Jails in Mac OS X like in FreeBSD or Solaris Zones? No. The closest you can get is a heavyweight (and costly) virtualization solution such as Parallels Server. This email sent to site_archiver(a)lists.apple.com

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Re: Mac OS X Jails
by Tim Murison 30 Jul '09

30 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcoRLHHc8qQPhouwykK+nFhvEAi6RQ== Thread-topic: Mac OS X Jails User-agent: Microsoft-Entourage/12.20.0.090605 On 30/07/09 11:33 AM, "z3r0_f4ct0r(a)mac.com" <z3r0_f4ct0r(a)mac.com> wrote: > Is it possible to create Jails in Mac OS X like in FreeBSD or Solaris > Zones? > > I haven't found any information on this. Are the sandbox_* functions what you mean? *********************************************************************** This e-mail and its attachments are confidential, legally privileged, may be subject to copyright and sent solely for the attention of the addressee(s). Any unauthorized use or disclosure is prohibited. Statements and opinions expressed in this e-mail may not represent those of Radialpoint. Le contenu de ce courriel est confidentiel, privilégié et peut être soumis à des droits d'auteur. Il est envoyé à l'intention exclusive de son ou de ses destinataires. Il est interdit de l'utiliser ou de le divulguer sans autorisation. Les opinions exprimées dans le présent courriel peuvent diverger de celles de Radialpoint. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Mac OS X Jails
by z3r0_f4ct0r＠mac.com 30 Jul '09

30 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com I haven't found any information on this. Thanks, Juan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Is it possible to create Jails in Mac OS X like in FreeBSD or Solaris Zones? This email sent to site_archiver(a)lists.apple.com

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RE: Filling in a struct timespec with the current date?
by Karan, Cem (Civ, ARL/CISD) 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcoQeDVljQtCD2KDRgqkW2TaaN2/hQAFSBLQ Thread-topic: Filling in a struct timespec with the current date? Terry Lambert wrote on Wednesday, July 29, 2009 2:12 PM <<SNIP>> > > Is there a way to tell what the accuracy is from the > > mach_timebase_info struct? E.g., the greatest common denominator > > between numer and denom is the accuracy of the clock in nanoseconds? > > Actually, that's a somewhat interesting question, and its > answer is one reason the RT functions haven't been back-filled. > > And honestly the best place to ask the question is probably a > site like "Tom's Hardware". But I'll give a shot at a 50,000 > ft view explanation. > > The answer is that you can treat it as monotonically > increasing, fairly high resolution, with variable accuracy > under less than 100% load, moderated by thermal and other > power management considerations. > > Intel chips in general don't have as accurate real time > clocks as even the older PPC systems, which had specific > direct support in non- switched support chips. > > By contrast, the more accurate clocks on Intel are generally > implemented using cycle counters (TSC style), and doing a > bunch of math to account for entry and exits for various C states. > > In addition, the actual counters are not technically > monotonic; that is, there is a jitter in accuracy which is > relative to the ratio between two MSRs on the CPU, and that's > used to "adjust" the TSC, e.g. > when events like the HPET timer, which is lower resolution, > wakes the CPU out of a power management C state, such as "deep C4". > > In addition, modern CPUs support "burst modes", where they > will internally overclock within their thermal envelope, > while under load, and likewise they will internally reduce > voltage and retard the clock under thermal pressure or reduced load. > > All of this code is outside the kernel proper, and uses > proprietary information from the CPU vendor, and is > intimately tied to the hardware. > > Ultimately, the code is very complicated to do what it does, > and what it does as far as timers is model the power state > and state transition latencies with sufficient precision that > what you end up with is a fairly accurate clock at the time > you read it. This is of course minus some accuracy for the > cycle count for the instructions for the read and the math > that happens to get it into an absolute time number, which > might be happening at a clock rate other than the rated clock > rate, if the CPU is bursting, thermal throttling, or under > less than full load. > > So the short answer after all that is "mostly accurate, but > not as accurate as if there were dedicated high resolution > RTC hardware, accessible on a fast bus, backing it up, > independent of the CPU itself". > > Most system designers these days claim that the unit of > measure of system performance isn't its CPU clock speed, it's > BTU and milliwatt- hours. Thank you for the explanation, I didn't realize it was that complicated on x86 chips. OK, in that case, I'll use it, but with the caveat that although it is probably the best clock I have available, its accuracy can be quite off (but no more off than any other clock I have access to) Thanks, Cem Karan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Filling in a struct timespec with the current date?
by Terry Lambert 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Terry Lambert wrote on Tuesday, July 28, 2009 2:51 PM <<SNIP>> Or if he needs better resolution, mach_absolute_time(), which is well documented at <http://developer.apple.com>. <<SNIP>> -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Jul 29, 2009, at 5:05 AM, "Karan, Cem (Civ, ARL/CISD)" <CKaran(a)arl.army.mil > wrote: OK, the best documentation I've found for this is at http://developer.apple.com/qa/qa2004/qa1398.html and I whipped up a quick test program to ensure I knew what I was doing with it. Now my question concerns accuracy; I know that mach_absolute_time() resolves to one nanosecond, but what is the accuracy? Is there a way to tell what the accuracy is from the mach_timebase_info struct? E.g., the greatest common denominator between numer and denom is the accuracy of the clock in nanoseconds? This won't affect my current code, but I'd like to stick it into my own documentation so whenever I reuse this code I know what I'm getting in to. Actually, that's a somewhat interesting question, and its answer is one reason the RT functions haven't been back-filled. And honestly the best place to ask the question is probably a site like "Tom's Hardware". But I'll give a shot at a 50,000 ft view explanation. The answer is that you can treat it as monotonically increasing, fairly high resolution, with variable accuracy under less than 100% load, moderated by thermal and other power management considerations. Intel chips in general don't have as accurate real time clocks as even the older PPC systems, which had specific direct support in non- switched support chips. By contrast, the more accurate clocks on Intel are generally implemented using cycle counters (TSC style), and doing a bunch of math to account for entry and exits for various C states. In addition, the actual counters are not technically monotonic; that is, there is a jitter in accuracy which is relative to the ratio between two MSRs on the CPU, and that's used to "adjust" the TSC, e.g. when events like the HPET timer, which is lower resolution, wakes the CPU out of a power management C state, such as "deep C4". In addition, modern CPUs support "burst modes", where they will internally overclock within their thermal envelope, while under load, and likewise they will internally reduce voltage and retard the clock under thermal pressure or reduced load. All of this code is outside the kernel proper, and uses proprietary information from the CPU vendor, and is intimately tied to the hardware. Ultimately, the code is very complicated to do what it does, and what it does as far as timers is model the power state and state transition latencies with sufficient precision that what you end up with is a fairly accurate clock at the time you read it. This is of course minus some accuracy for the cycle count for the instructions for the read and the math that happens to get it into an absolute time number, which might be happening at a clock rate other than the rated clock rate, if the CPU is bursting, thermal throttling, or under less than full load. So the short answer after all that is "mostly accurate, but not as accurate as if there were dedicated high resolution RTC hardware, accessible on a fast bus, backing it up, independent of the CPU itself". Most system designers these days claim that the unit of measure of system performance isn't its CPU clock speed, it's BTU and milliwatt- hours. This email sent to site_archiver(a)lists.apple.com

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Re: Filling in a struct timespec with the current date?
by Esteban Bodigami 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=afxtLkvwu9NksFIUNdpWhWAqElo7OBFH5M/28DkUNN4=; b=TkuCMnd9QvRnMQT7L9iBZkLaAX8kcplh9dO0Z2vroggaw5HKeGqCwCkniYA5/iY25L NAHh+3JESjOhxU1ydfpeJ0d4e2nycjRQd9fJOFaMaOl/rDnmX13R+0q+bAxaNAEa8DPg 6CeSbetD7kIsjpGopDCmzYL+f2NX7D6gyLIIM= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=VzrEYzN13k9Zbces+fvaPe1WlW+yRc56uSTPb4GDTySD1d5KTv6rlbgJ1rO7MDRgGQ p70hwhIFdLw6/Z735ndM2G8B5ZBS3pPRp+h9yL+T6fynUHyA+28M5vCWC7hrm/QUo/Js aDj36ThEE/4mPyA4IqfAio+q7h+Fs4F7swUdA= // Calculate the duration. elapsed = end - start; // Convert to nanoseconds. // Have to do some pointer fun because AbsoluteToNanoseconds // works in terms of UnsignedWide, which is a structure rather // than a proper 64-bit integer. elapsedNano = AbsoluteToNanoseconds( *(AbsoluteTime *) &elapsed ); return * (uint64_t *) &elapsedNano; 10−9 seconds and 10−8 seconds (1 ns and 10 ns) _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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RE: Filling in a struct timespec with the current date?
by Karan, Cem (Civ, ARL/CISD) 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcoPtHsvzHJigHWKSe25Tdk8NQGYPAAjAK+A Thread-topic: Filling in a struct timespec with the current date? Terry Lambert wrote on Tuesday, July 28, 2009 2:51 PM <<SNIP>> > Or if he needs better resolution, mach_absolute_time(), which > is well documented at <http://developer.apple.com>. <<SNIP>> OK, the best documentation I've found for this is at http://developer.apple.com/qa/qa2004/qa1398.html and I whipped up a quick test program to ensure I knew what I was doing with it. Now my question concerns accuracy; I know that mach_absolute_time() resolves to one nanosecond, but what is the accuracy? Is there a way to tell what the accuracy is from the mach_timebase_info struct? E.g., the greatest common denominator between numer and denom is the accuracy of the clock in nanoseconds? This won't affect my current code, but I'd like to stick it into my own documentation so whenever I reuse this code I know what I'm getting in to. Thanks, Cem Karan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Filling in a struct timespec with the current date?
by Esteban Bodigami 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=Mjsrpo9D0iERGnvywqP013TykJzZRh4lKEyH/c8rNc0=; b=NKTvq3cLNzkdorNPWSkRwzFGKyblYRG0JJo4lzIhV2yl0rwx85vARiZZwBkcmksYBn 3dGrwlSblazI5gie/POoZ7r4G8iLhZWUir6TRGIlFGN9VVCYPQaJyqdgdVeZfDQjWPS2 R364mRFyiVvnSP8uci14T0ZGMH69xz1XHExMA= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=N9yvngOLqkbiZptb6WKHedUWcdVYN5PZnY65n3iOLAYBif1O/pZAr7jXoU5vC4JWu7 ursiFVMDNZ/1XxE4LSzzRZpPRmtTs8ELhluslktZxrK8CUwShnURjoRQMVvtJZlerJir 9daccYCbB8zoL0rbSKpzTX9tYoI0+GcuRAeDg= _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Filling in a struct timespec with the current date?
by Esteban Bodigami 29 Jul '09

29 Jul '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=wcAi0NAuwM5H7xXzd/Xu/IFyNnuqWzAh7Im3zt3H7RY=; b=OOcivp0D67gfMPubPOiBg6Iuuvp+YWiXejtzEyPEsbHNunioC/lhaBocps2j41YfYj wD0bqiaJdDvxgrUHm0MsNp89zPh2RUCONPI1lJ8mE74Ok+OpJWKx9SM9Ed9RQ2amU9Nq UU5cBLxtM/7PWWg0o2HAxfOzX8AtZzzZREzBE= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=CXnZ1iK92k/IkfUHdKGU2ypenkjAyBHAzMANTSyRoi0cV9x3U/hub6VvvxdWrLGYBG xCjLlxAg0dubOxKnAOLFqqeLjBKa2UzvpFXGQFiuPwTebe9W/aPxtrdSXPaxINpT6LN1 K5k1/3KWPRgtWt+Sn3luDGkUn3T1IGN9IhI2w= _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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