Re: [RFC] New Driver Model for 2.5

Michael H. Warfield
2001-10-24T16:36:18Z

On Wed, Oct 24, 2001 at 09:19:45AM -0700, Linus Torvalds wrote:

> On Wed, 24 Oct 2001, Alan Cox wrote:

> > Assuming you want to synchronize the raid before suspend - a reasonably
> > policy but not essential then you'd have to shut down the raid before
> > sd, then sd would let the devices shut down which lets the controller
> > shutdown

> I will _refuse_ to have a kernel suspend that synchronizes the raid etc.
> That would make suspend/resume potentially take a _loong_ time.

If you have Magic SysRq enabled, would that do the job prior
to suspend? Typically with Pavel's swsusp package, I hit the Alt-SysRq-s
before hitting Alt-SysRq-d to suspend him. Does Alt-SysRq-s synchronize
a raid? Of course, at that point, the choice to take the "_loong_ time"
is in user space - meat space, user space - since I chose to hit that
key combination.

> If you want to synchronize your raid thing, make the user-level thing that
> triggers the suspend do it. Same goes for things like "sync network
> filesystems" etc. This is not a kernel level issue, and the kernel
> shouldn't even try to do it.

What does the Alt-SysRq-s combination do about networks then?

> If somebody has pending stuff over NFS and suspends, and when it comes
> back it's not on the network any more, that is 100% equivalent to removing
> a PCMCIA network card while running. It's supposed to work - but if you
> lose data that's YOUR problem, not the kernels.

> Linus

Mike
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