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

[Ed Maste]

On 28 June 2013 09:05, Peter Maydell <address@hidden> wrote:
> On 28 June 2013 14:03, Paolo Bonzini <address@hidden> wrote:
>> Il 28/06/2013 14:54, Ed Maste ha scritto:
>>> An objection seemed to be that it is not really needed yet, but as
>>> pointed out by Peter this isn't really the case.  This patch brings us
>>> (FreeBSD) in line with per-thread data semantics on Linux and is used
>>> by qemu system emulation as well.
>>
>> It brings it in line with Linux, even though FreeBSD has the same need
>> for TLS as OpenBSD and Windows (i.e. none).  In other words, we go from
>> two cases (need TLS and uses it, has no TLS and doesn't need it) to
>> three (we add "uses TLS with no need for it").
>
> I don't understand what you mean by "no need for it". We are
> already multithreaded in system mode, so this is simply
> making FreeBSD do the same thing as Linux. That seems like a
> clear improvement to me.

I agree; even if this is a hack, it's a well-tested one.  Indeed, even
on a FreeBSD host most users already have this change, as they have
built from ports or used prebuilt packages.