Re: libc recently more aggressive about pthread locks in stable ?
On 07/11/16 at 21:52 +0100, Lucas Nussbaum wrote:
> On 06/11/16 at 17:41 -0200, Henrique de Moraes Holschuh wrote:
> > On Sun, 06 Nov 2016, Ben Hutchings wrote:
> > > It's worth noting that TSX is broken in 'Haswell' processors and is
> > > supposed to be disabled via a microcode update. I don't know whether
> > > glibc avoids using it on these processors if the microcode update is
> > > not applied. (Linux doesn't appear to hide the feature flags.)
> > It does avoid it. For glibc libpthreads, Debian has blacklisted Intel
> > TSX use [in libpthreads] on all of Haswell and much of Broadwell.
> > But anything else *will* attempt to use it, people query cpuid directly
> > for these things. You need a hypervisor that filters cpuid().
> How can one know what glibc does on a given CPU? (preferably without
> access to the hardware)
Answering myself, the relevant patch is