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-----Original Message----- |
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From: richard.j.fish@×××××.com on behalf of Richard Fish |
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Sent: Sun 9/10/2006 2:30 PM |
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To: gentoo-user@l.g.o |
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Subject: Re: [gentoo-user] changing CHOST |
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|
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On 9/10/06, Timothy A. Holmes <tholmes@×××××××××.net> wrote: |
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> Richard: |
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> |
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> I got this one - thanks, the problem is that im getting conflicting |
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> advice from multiple sources. |
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|
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I think the problem with this is (and I don't mean to offend when I |
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say this...) that the people who would be able to figure out how to |
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successfully change CHOST on a live system have never have to do so, |
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because they set it right from the start. |
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|
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So my advice is based on: |
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|
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http://article.gmane.org/gmane.linux.gentoo.user/169260 |
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|
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As well as forums threads such as: |
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|
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http://forums.gentoo.org/viewtopic-t-386633.html |
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|
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(BTW, one has to be a bit careful on the forums, as some of those |
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threads have answers from people who recommend merging system and |
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world twice each....which is pretty much useless.) |
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|
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> You cant do that no matter what |
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|
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Pretty sure this isn't true. But it would be wrong to suggest that it |
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is an easy thing to change, or say that there is some method that |
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guarantees you won't end up booting from your live CD to repair |
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things. |
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|
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> To |
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> You don't want to do that |
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|
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This one seems entirely up to you. At this point in Gentoo, you |
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either have to change CHOST, or add ">=sys-libs/glibc-2.4" to |
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/etc/portage/package.mask, since 2.4 is nptl only, and that requires |
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better than i386. |
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|
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> To |
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> It wont do any good |
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|
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If this was the entire answer, it is simply clueless. Using the CHOST |
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that matches your processor lets gcc use more effecient instructions |
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for newer processors. This is what makes nptl so more efficient than |
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linuxthreads, because it uses processor instructions specifically |
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designed for multi-CPU synchronization. |
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|
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Now whether the improvements are worthwhile or not is a subjective |
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thing, and one could argue that it isn't worth the effort. This goes |
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back to the previous point. |
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|
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> To |
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> Bootstrap wont run |
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|
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Sounds like a bug. |
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|
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> To |
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> No need for bootstrap, just change and do the emerges |
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|
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Well I would have thought so too, but that hasn't worked for some |
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people. Again, there is no definitive guide on changing CHOST. The |
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safest option is to boot from a livecd and re-install using the new |
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CHOST. |
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|
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But if you are willing to go that far anyway, it can't hurt to try the |
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bootstrap.sh ; emerge -e system ; emerge -e world sequence. |
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Basically, if you make it through the emerge -e system part, you have |
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a sane base system and anything else that breaks indicates a problem |
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with the change in profile or gcc versions, not the change in CHOST. |
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|
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BTW, Darren's answer on this thread seems incorrect to me. Changing |
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CHOST is a pretty significant thing to tweak, certainly as significant |
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as changing gcc versions, and you really should re-merge *everything* |
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to make sure your something doesn't wind up broken. |
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|
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> Im a bit confused to be honest |
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|
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That's ok. It isn't an easy question to answer unfortunately. |
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|
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-Richard |
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-- |
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gentoo-user@g.o mailing list |
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|
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Richard: |
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|
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thanks a great deal for your answer -- it is extremely helpful. |
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|
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I think i will give it a shot, the system in question right now is only my rsync mirror -- it as additional tasks planned to be installed, but that hasn't happened yet. if i can get it to run, then it is cool, but if not, i havent lost a great deal. I do however have a couple other production boxes that I REALLY dont want to have to rebuild that might (i havent checked yet) be built using the same stage 3 -- they are running ok, speeds and processor loads look ok, so if this breaks this box, im not going to attempt it on the other ones. |
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I'll let you know how it goes |
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|
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TIM |