Prefaulting for i/o buffers

[Ivan Klymenko]

В Sun, 12 Feb 2012 22:43:37 +0200
Konstantin Belousov <kostikbel at gmail.com> пишет:

> On Sun, Feb 12, 2012 at 10:37:54PM +0200, Ivan Klymenko wrote:
> > В Sun, 12 Feb 2012 22:24:13 +0200
> > Konstantin Belousov <kostikbel at gmail.com> пишет:
> > 
> > > On Sun, Feb 12, 2012 at 10:14:56PM +0200, Ivan Klymenko wrote:
> > > > В Fri, 3 Feb 2012 21:37:19 +0200
> > > > Konstantin Belousov <kostikbel at gmail.com> пишет:
> > > > 
> > > > > http://people.freebsd.org/~kib/misc/vm1.3.patch
> > > > 
> > > > I have FreeBSD 10.0-CURRENT #0 r231526M: Sat Feb 11 23:06:18 EET
> > > > 2012 ivan at nonamehost:/usr/obj/usr/src/sys/mk10  amd64
> > > > 
> > > > my system is patched
> > > > http://people.freebsd.org/~kib/drm/all.13.2.patch (I do not
> > > > know is the important point is whether or not)
> > > > 
> > > > When using this patch vm1.3.patch or 1.4 or 1.5 or ... including
> > > > http://people.freebsd.org/~kib/misc/vm1.9.patch the system works
> > > > fine in the console, but when loaded into a graphical
> > > > environment - a system gets of global lock (even the mouse
> > > > cursor does not move)
> > > > - only reset helps
> > > > 
> > > > I'm using Gnome GUI + compiz...
> > > 
> > > I cannot make anything with this report, since it obviously
> > > misses any data on the deadlock.
> > 
> > Definitely yes :) but
> > 
> > > 
> > > BTW, I just put vm1.10 which allows buildworld over NFS to finish
> > > successfully.
> > 
> > my kernel config file is assembled with the options
> > options KDB_TRACE
> > options KDB # Enable kernel debugger support.
> > options DDB
> > also use the patch http://people.freebsd.org/ ~
> > kib/drm/all.13.2.patch where not yet implemented the transition to
> > the console - how do I get at least some data using the
> > break-to-debugger Ctrl + Alt + ESC?
> 
> Switching the virtual consoles probably would not work on the
> deadlocked system anyway, since X server needs to process this
> operation regardless of the presence of KMS. The more important, but
> not yet realized premise of KMS is the ability to enter the kernel
> debugger on the graphical console without switching X session
> console. But this indeed not implemented.
> 
> I suspect that the serial console, or software watchdog and some ddb
> script (see ddb(8)) are the only ways forward.

That is, should I try to add to the kernel configuration options
SW_WATCHDOG and in /etc/rc.conf watchdogd_enable="YES" and after
global lock to happen - expect a miracle? :)
because the other possibilities I have not ...