tar hangs on 715/75 (spinlock problem)

Richard Hirst rhirst@linuxcare.com
Mon, 22 Jan 2001 22:17:04 +0000


On Mon, Jan 22, 2001 at 09:32:19PM +0000, Richard Hirst wrote:
> On Mon, Jan 22, 2001 at 04:50:14PM +0000, Richard Hirst wrote:
> > Hi,
> >   tar (and nscd) hang on my 715/75.  Same binaries/libraries work on
> > the B180.  The hang is in __pthread_acquire() called from
> 
> This is because ldcw behaves differently on the 715/75 and the B180.

Grant tells me spinlock words have to be the first word of a cacheline,
so that would be why my example code broke.  However, libpthreads uses
spinlocks and doesn't appear to force any alignment.

I think the libpthreads spinlock definitions come from
glibc/linuxthreads/sysdeps/pthread/bits/pthreadtypes.h, struct
pthread_mutex_t, spinlock is inside __m_lock.  No alignment is
specified.  When debugging tar, I found the spinlock word at
0x4014df4c.

Richard