deadlocks with intr NFS mounts and ^Z (or: PCATCH and sleepable locks)

[Kris Kennaway]

Bruce Evans wrote:

> These problems seemed to go away, but right now the following problem
> like the second set above occurs consistently (I first noticed this
> last week):
> 
>     Script started on Sat Jun 20 02:32:51 2009
>     pts/0:bde at ref8-i386:~/sys7/i386/compile> sh zm
>     ^Z
>     [1]+  Stopped                 sh zm
>     pts/0:bde at ref8-i386:~/sys7/i386/compile> %
>     sh zm
>     *** Stopped -- signal 18
>     *** Stopped -- signal 18
>     *** Stopped -- signal 18
>     *** Signal 1
>     *** Signal 1
>     *** Signal 1
>     `all' not remade because of errors.
>     linking kernel
>     ^C
>     pts/0:bde at ref8-i386:~/sys7/i386/compile> exit
> 
>     Script done on Sat Jun 20 02:34:41 2009
> 
> The shell script zm builds 6 kernels in parallel using make -k -j8 for
> each.  Signal 18 is SIGTSTP.  Receiving this is normal, but the shell
> shouldn't print any meesages about it.  Signal 1 is SIGHUP.  This
> shouldn't occur.  On another run, ISTR getting messages about i/o
> errors or unrestartable processes.  Anyway, the messages about signals
> are associated with failing jobs in the build.

That's a long standing bug that I don't think is limited to NFS.  I 
first started seeing it several years ago after some changes to make(1), 
but I don't recall if phk disputed that they were to blame.

Kris