Re: [Qemu-devel] [PATCH] tls.h: Enable TLS on FreeBSD

[Paolo Bonzini <pbonzini@redhat.com>]

Il 24/06/2013 21:21, Ed Maste ha scritto:
> Signed-off-by: Ed Maste <emaste@freebsd.org>
> ---
> I have had this in a local tree for some time, and it is needed by the
> BSD-user work that is now being proposed.

At this time, qemu/tls.h is really just for cpu_single_env, so I think
this patch should be applied together with the bsd-user patches that
need it.

> As an aside, an abstraction was recently proposed for Open vSwtich that
> can use any of _Thread_local, __thread, or pthread_getspecific() which
> may make a convenient reference for someone wishing to implement one of
> the TODOs: http://openvswitch.org/pipermail/dev/2013-June/028665.html

I and Stefan Hajnoczi have almost the same idea implemented in QEMU
(except that get_foo() returns a pointer to the variable).  But
pthread_get/setspecific would be too slow for cpu_single_env, so we're
just switching to __thread for cpu_single_env (for Linux in our patches,
but you can add FreeBSD too once it's needed).

Paolo