Today is a big day, for me, for Ed Schouten and for FreeBSD (And it’s consumers ofcourse). Why? Ed Schouten today integrated his MultiProcessorSafe (MPSAFE) implementation of the TTY Layer for FreeBSD. From the beginning that I heared about the project, Ed and I had been in contact, both working at the same company (Snow B.V.), we flew to Canada together (Facilitated and sponsored by Snow B.V.), visited eachother, been in contact for ages (or at least it feels like ages, which is a positive point in this case). Ed also gratuated in the meantime by working on this TTY layer. So a lot of good things had been evolved because of this!
For FreeBSD this means that finally the TTY layer is GIANT-less. One more big obstacle removed to entirely getting rid of the GIANT lock 
, as Poul-Henning Kamp mentioned at some point: This is one of the latest chapters that needed rewriting (since a long time as far as I know).
So I am really happy about this. Good Work Ed!!!
Thanks
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well, i thought we got rid of that GIANT lock with the ULE scheduler… but hey, anything helping remove an implicit or assumed global lock that will limit performance, and force serialized code, will be great. Cant wait for FreeBSD to be able to run on a cloud/grid/farm/cluster with a reasonable amount of robustness
Well, the processing part was GIANT lock free. But several subsystems still use the GIANT lock (just boot your computer and you’ll see those various systems). By having the TTY-layer GIANT-lock free, we can make the modules that use this (and are still under GIANT locking) MPsafe at some point. I see this as important infrastructure that we can continue to build upon.
And not only that, the new code is more modular and makes new things possible (hopefully); so perhaps something like ethernet-tty’s or other fancy things
[...] Noch nicht dort erwähnt aber just eingeflossen: der neue TTY-Layer in Current. Giant-free sorgt dieser somit ebenso für eine völlig neue Dimension der Arbeit in FreeBSD. In what’s cooking kann jeder FreeBSD-Interessierte darüber hinaus regelmäßig den aktuellen Wasserstand in der Entwicklung nachlesen. [...]
[...] Today is a big day, for me, for Ed Schouten and for FreeBSD (And it’s consumers ofcourse). Why? Ed Schouten today integrated his MultiProcessorSafe (MPSAFE) implementation of the TTY Layer for FreeBSD. From the beginning that I heared about the project, Ed and I had been in contact, both working at the same company (Snow B.V.), we flew to Canada together (Facilitated and sponsored by Snow B.V.), visited eachother, been in contact for ages (or at least it feels like ages, which is a positive point in this case). Ed also gratuated in the meantime by working on this TTY layer. So a lot of good things had been evolved because of this! [...]