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Subject: Re: [Qemu-devel] [Qemu-trivial] [PATCH] tls.h: Enable TLS on FreeBSD
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-trivial@nongnu.org, Ed Maste <emaste@freebsd.org>, Michael Tokarev <mjt@tls.msk.ru>, qemu-devel <qemu-devel@nongnu.org>

Il 28/06/2013 15:05, Peter Maydell 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. 

cpu_single_env is protected by the BQL unless you're running on KVM.

Paolo