tree 1593d2a0f0ff19c4deb731d6079997e79989c8b1
parent 28ff4ef71795fe6f6c0cc06a04911c9ca09c2c11
author Rusty Russell <rusty@rustcorp.com.au> 1267042942 -0600
committer Rusty Russell <rusty@rustcorp.com.au> 1266983544 +1030

virtio: remove bogus barriers from DEBUG version of virtio_ring.c

With DEBUG defined, we add an ->in_use flag to detect if the caller
invokes two virtio methods in parallel.  The barriers attempt to ensure
timely update of the ->in_use flag.

But they're voodoo: if we need these barriers it implies that the
calling code doesn't have sufficient synchronization to ensure the
code paths aren't invoked at the same time anyway, and we want to
detect it.

Also, adding barriers changes timing, so turning on debug has more
chance of hiding real problems.

Thanks to MST for drawing my attention to this code...

CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>