Re: [gentoo-dev] Re: Re: Downgrading glibc?
> "MH" == Michael Haubenwallner writes: MH> I've heard a colleague of mine debugged for 50(!) hours after moving MH> some quite old application to some recent Linux before he replaced a MH> memcpy by memmove, so this did ring some bells. MH> However, now he said this was on Ubuntu 10.04.1 LTS, having MH> glibc-2.11, so this might have been unrelated indeed. Check the archives of the glibc lists, as well as its bug db. There has been quite a bit of discussion there on that issue. It was added for sse3 some time ago; I beleive it was Intel engineers who contributed it for sse3, showing that it was inedeed faster on their chips to start at the high point and decrement the counter rather than starting at the low point and incrementing. The discussion in their lists does a better job of documenting the issue. -JimC -- James Cloos OpenPGP: 1024D/ED7DAEA6
Re: [gentoo-dev] Re: Re: Downgrading glibc?
On 02/16/2011 11:06 AM, Michael Haubenwallner wrote: > So I'm fine with Gentoo shipping vanilla memcpy, I'm just curious > if next RHEL will do. I'd be surprised as hell to find out Red Hat changed this in current RHELs (5 and 6) during their lifetime. On the other hand I'd be equally surprised if Red Hat wouldn't use upstream implementation in future products. If Fedora is any example, they will keep upstream implementation. Also RHEL 6 is still pretty fresh, so there are quite a few years until RHEL 6.0 goes EOL so software vendors have time to fix their problems :-) -- Stanislav Ochotnicky PGP: 7B087241 jabber: stanis...@ochotnicky.com signature.asc Description: OpenPGP digital signature
Re: [gentoo-dev] Re: Re: Downgrading glibc?
On 02/11/11 16:24, Diego Elio Pettenò wrote: > Il giorno ven, 11/02/2011 alle 14.23 +0100, Michael Haubenwallner ha > scritto: >> >> But both that document as well as uncountable lines of source code are >> rather old. >> While the source code isn't that large a problem for Gentoo, existing >> binaries >> without source code still are. > > Beside flash what else is involved for now? We can decide that once > that's defined. I've heard a colleague of mine debugged for 50(!) hours after moving some quite old application to some recent Linux before he replaced a memcpy by memmove, so this did ring some bells. However, now he said this was on Ubuntu 10.04.1 LTS, having glibc-2.11, so this might have been unrelated indeed. Anyway, running old applications on recent Linux is quite common in "enterprise" world (where Gentoo might not be such a big player). So I'm fine with Gentoo shipping vanilla memcpy, I'm just curious if next RHEL will do. /haubi/ -- Michael Haubenwallner Gentoo on a different level
Re: [gentoo-dev] Re: Re: Downgrading glibc?
On 02/11/2011 05:13 PM, Diego Elio Pettenò wrote: > Il giorno ven, 11/02/2011 alle 15.37 +0100, Sebastian Pipping ha > scritto: >> Portage will propose a downgrade of glibc on emerge-update-world, okay. >> How bad would that be? Does it cause any other trouble? > > And glibc will refuse to downgrade unless you hack the ebuild. Now let's > say that the user rebuilt gcc after the glibc upgrade, and now forces > downgrade; after forcing downgrade, gcc will fail to find the symbols > with higher versioning (GNU versioning), which means it won't run. > >> In your eyes, is there anything we can do to improve the current situation? > > Every time a base package changes that could cause huge breakage, mask, > send a message to q...@gentoo.org to start up testing ebuild $foo with an > unmask list, and wait till we give the go before unmasking. > That will be definately done for libpng-1.5.1 that just hit tree with KEYWORDS="". It turns most, if not all deprecation warnings from libpng-1.4.x series to fatal errors. ABI break, .la files drop and the fun of 90% of packages not building against it \o/ - Samuli
[gentoo-dev] Re: Re: Downgrading glibc?
Il giorno ven, 11/02/2011 alle 14.23 +0100, Michael Haubenwallner ha scritto: > > But both that document as well as uncountable lines of source code are > rather old. > While the source code isn't that large a problem for Gentoo, existing > binaries > without source code still are. Beside flash what else is involved for now? We can decide that once that's defined. -- Diego Elio Pettenò — Flameeyes http://blog.flameeyes.eu/
[gentoo-dev] Re: Re: Downgrading glibc?
Il giorno ven, 11/02/2011 alle 15.37 +0100, Sebastian Pipping ha scritto: > Portage will propose a downgrade of glibc on emerge-update-world, okay. > How bad would that be? Does it cause any other trouble? And glibc will refuse to downgrade unless you hack the ebuild. Now let's say that the user rebuilt gcc after the glibc upgrade, and now forces downgrade; after forcing downgrade, gcc will fail to find the symbols with higher versioning (GNU versioning), which means it won't run. > In your eyes, is there anything we can do to improve the current situation? Every time a base package changes that could cause huge breakage, mask, send a message to q...@gentoo.org to start up testing ebuild $foo with an unmask list, and wait till we give the go before unmasking. -- Diego Elio Pettenò — Flameeyes http://blog.flameeyes.eu/
