On Tue, Feb 20, 2018 at 07:52:49PM +0100, Otto Moerbeek wrote:
> On Tue, Feb 20, 2018 at 08:58:47AM +0100, Otto Moerbeek wrote:
>
> > On Tue, Feb 20, 2018 at 08:52:20AM +0100, Mark Kettenis wrote:
> >
> > > > Date: Mon, 19 Feb 2018 13:49:48 +0100 (CET)
> > > > From: Mark Kettenis <[email protected]>
> > > >
> > > > The diff below attempts to make the arm64 pmap "mpsafe" and enables MP
> > > > support. This diff survived a full build on my Firefly-RK3399 board.
> > > > It also seems to work on the Overdrive 1000. It might even work on
> > > > the Raspberry Pi 3. I'd appreciate it if people could play with this
> > > > on the Raspberry Pi and other arm64 hardware they have.
> > > >
> > > > I tried to follow a strategy for making the pmap "mpsafe" that more
> > > > closely resembles what we did for our other architectures, although I
> > > > looked at Dale Rahn's diff as well. It seems I fixed at least some
> > > > bugs in the process. But I'm sure there are bugs remaining. I may
> > > > even have introduced new ones. So do expect this to crash and burn,
> > > > or at least lock up.
> > > >
> > > > I'm also interested in people testing the normal GENERIC kernel with
> > > > this diff, especially building ports. There are some changes in there
> > > > that could affect non-MP as well.
> > >
> > > Here is a slightly better diff that removes a potential lock ordering
> > > problem, removes a redundant splvm and moves some code around to avoid
> > > a level of indentation. Gaining confidence, so I'm looking for ok's
> > > now.
> >
> > I have been running you diff on my rpi (together with jsg firmware update).
> >
> > My rpi has hung twice now while doing a make -j4 in the clang part of
> > the tree.
> >
> > The last top screen shows it using swap (around 400M) and has three
> > c++ processes each with resident size around 200M.
> >
> > I'll try this diff now.
>
> Not much change with this diff compared to the first. The system
> functions more or less, but I'm seeing:
>
> - No processes being scheduled on CPU 0
> - A hang on reboot
> - slaacd is not table to configure the ipv6 correctly, the address
> remains "tentative" and packets do not flow.
>
> Switching to single user mode, init complains it cannot kill all
> processes. It turns out the main slaacd process hangs and cannot be
> killed (not even with kill -9).
>
> All this does not happen running a non-MP kernel.
>
> -Otto
A bit more info:
When displaying system processes with top, this is what I see:
79636 root -22 0 0K 121M onproc/0 - 0:05 99.71% idle0
519 otto 28 0 1040K 1848K onproc/3 - 0:01 0.05% top
58718 root -5 0 0K 121M sleep/3 - 218:42 0.00% idle1
58489 root -5 0 0K 121M onproc/1 - 218:37 0.00% idle3
41386 root -5 0 0K 121M onproc/2 - 218:28 0.00% idle2
Compared to and amd64 system, it shows idle0 on cpu0 taking
cpu time, but not actually accumulating it?
amd64 system:
49951 root -22 0 0K 10M onproc/0 - 406.8H 0.00% idle0
51048 root -22 0 0K 10M onproc/3 - 406.4H 0.00% idle3
60166 root -22 0 0K 10M idle - 405.6H 0.00% idle1
9554 root -22 0 0K 10M onproc/2 - 405.2H 0.00% idle2
-Otto
