Re: It's almost 2016 and when (single-threaded) Emacs hangs, you gotta be smashing your keyboard!

[Bob Proulx <bob@proulx.com>]

Pascal J. Bourguignon wrote:
> Alexander Shukaev writes:
> > In this particular case, I'm talking about Linux and directories
> > mounted from network.
> 
> Yeah, right.
> 
> This freezes unix, not emacs.  You might prefer to access remote files
> using tramp.

I want to emphasize this.  If you are accessing files over NFS and for
whatever reason the NFS server goes away this causes the NFS client in
the local kernel to wait.  The "freeze" you are seeing is a freeze in
the NFS client and not Emacs.  The problem is in the kernel not emacs.

NFS client is implemented in the kernel.  When it locks up there is
absolutely nothing an application can do to unlock the kernel.  This
has been a plague on NFS forever.  Problems with the NFS client are
the one thing that may require the workstation to be rebooted.
Because if it were an application in userspace one could kill and
restart it.  But because NFS is implemented in the kernel the only way
to kill and restart the kernel is to reboot.

The only way to win is not to play.  Which is what Pascal suggests
with using emacs tramp to avoid nfs client and instead use ssh or
other to access those files.  Because tramp operates entirely in
userspace it can't lock up the same way.

Bob

P.S. Emacs has been rock solid for me for the last decade.  I can't
remember the last time I experienced an emacs crash.  Bugs in
behavior?  Sure.  But no crashes.