Re: kern/55781: more rump fixes

[Ruslan Nikolaev <nruslan_devel%yahoo.com@localhost>]

No, Christos, the point is different here.

Only the bootstrap CPU calls rump_init() even after our change.

However, during rump_init() other CPUs are already scheduled some tasks, 
so we need to wake them up, we cannot simply wait until rump_init() 
finishes. If we wake them too early (i.e., before rump_init()), their 
state will not be properly initialized yet. So, we need to wake them up 
while in rump_init() but only *after* their state is fully initialized.

So, this is when the bootstrap CPU will call the callback function.


Note that other CPUs will not call rump_init(), they will simply 
schedule some queued tasks.


Does it make sense?


Ruslan


On 11/4/20 10:43 AM, Christos Zoulas wrote:
> > On Nov 3, 2020, at 8:00 PM, Ruslan Nikolaev <nruslan_devel%yahoo.com@localhost 
> > <mailto:nruslan_devel%yahoo.com@localhost>> wrote:
> >
> > Thanks for the feedback! I'll see if I can fix it. In the meantime, I 
> > also posted one more SMP-related patch: kern/55781
> >
> > We also have rump (glue) files for new drivers such as ixgbe, nvme, 
> > etc -- we will post them as well.
>
> How does 55781 work? doesn't "rump_inited" prevent the function to be 
> entered from other cpus?
>
> https://github.com/ssrg-vt/src-netbsd/blob/168bf207298443ea437f83cd5594d8907dd0be97/sys/rump/librump/rumpkern/rump.c#L238
>
> christos