tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Status of revivesa

On Mon, Sep 29, 2008 at 10:39:18AM -0400, Christos Zoulas wrote:
> On Sep 29,  9:12am, (Andrew Doran) wrote:
> -- Subject: Re: Status of revivesa
> | On Fri, Sep 26, 2008 at 09:58:00AM -0400, Christos Zoulas wrote:
> | 
> | > On Sep 26,  9:16pm, (Izumi Tsutsui) 
> wrote:
> | > -- Subject: Re: Status of revivesa
> | > 
> | > | How many users will actually be screwed seriously with SA,
> | > | rather than pleased by advantages on other features?
> | > 
> | > Everyone who uses common applications from pkgsrc and will need to 
> re-build.
> | > Even perl is broken.
> | 
> | Do you have any evidence to back that up?
> | 
> | Here's perl built on 4.0 and running in a 4.0 chroot with -current kernel,
> | and with the drop-in compat libpthread I mentioned earlier:
> I have not tried that [with the drop-in compat libpthread], but without it
> it does not work... Ideally one could construct a libpthread that would
> work with both SA and non SA threads [by checking on the availability of
> the sa syscalls or even the kernel version] so that people can switch
> between current and 4.0 kernels. Is that possible, and is that a better
> alternative than revivesa?

It might be possible, but "you have to update this library" is not the 
same level of backwards binary compat we have had in the past. ;-)

What still isn't clear to me is what exactly the negatives are of 

The biggest one I'm hearing is that a number of people HATE it. Flat out 
HATE it. I'm not really sure what to do with this one, since it's hard to 
understand. It's an emotion, and we usually try to stick to technical 

The SA that's on revivesa is a kernel option. If you don't want it, don't 
enable it. If we find a catastrophic flaw in it (or security issue) late 
in the 5.0 release proces, we turn it off in the default kernels and tell 
people to only re-enable it with caution.

SA is not becoming, nor do I ever envision it becoming, the default 
threading out-of-the-box for NetBSD. Some sites may eventually prefer it, 
but that's a specialized situation. And something an admin would have to 
explicitly select.

Take care,


Attachment: pgpoVbYh59I92.pgp
Description: PGP signature

Home | Main Index | Thread Index | Old Index