On Sat, Sep 20, 2014 at 12:05:54AM -0400, Carlos O'Donell wrote: > On Fri, Sep 19, 2014 at 9:59 PM, Henrique de Moraes Holschuh > <h...@debian.org> wrote: > > On Fri, 19 Sep 2014, Carlos O'Donell wrote: > >> On Fri, Sep 19, 2014 at 6:18 PM, Henrique de Moraes Holschuh > >> <h...@debian.org> wrote: > >> > On Fri, 19 Sep 2014, Henrique de Moraes Holschuh wrote: > >> >> I can live with that, and I think I can prepare a patch if you want me > >> >> to. > >> > > >> > Here's a minimal patch to glibc that should do it (compile tested). > >> > >> The GNU C Library only uses elision if built with > >> --enable-lock-elision=yes. > >> > >> All you need to do is not build glibc with this flag. > > > > Given Jessie's expected lifetime, I'd say the blacklist is a much better > > choice with the data currently available. > > Why not ignore this, call it a hardware problem, and let users update > the microcode if their devices are broken?
The real problem that we try to address here is not that we want to disable TSX on these machines because it's broken. What we want to address here is that users might upgrade the microcode from Linux (either during boot time or later), which will cause all processes using pthread (which also includes systemd) to die almost instantaneously. We might want to simply use --enable-lock-elision=no as currently no CPU support TSX (after microcode upgrade), but the problem will be there again once TSX support is added back to new CPUs. As the problem will have to be solved at some point, let's do it now, especially given that I hope that TSX will be added back during the lifetime of Jessie. I therefore think Henrique's approach is the correct one. It also means that we only need to blacklist TSX on machines which have a microcode update available. I am currently doing a test build with his patch, if everything goes well I'll merge it in Debian. Henrique: in that case it would be nice if you can forward this patch upstream for discussion. Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
