ptr_ring: READ/WRITE_ONCE for __ptr_ring_empty
authorMichael S. Tsirkin <mst@redhat.com>
Thu, 25 Jan 2018 23:36:29 +0000 (01:36 +0200)
committerDavid S. Miller <davem@davemloft.net>
Mon, 29 Jan 2018 17:02:53 +0000 (12:02 -0500)
commita259df36d1fbf25f0e4f649fdb84e4527e5640ed
treea5a2c6d057c491dc2235cd443e1bf7a6823d74b2
parent8619d384eb5e9256a9d4ebe96c1832ac9b9049d6
ptr_ring: READ/WRITE_ONCE for __ptr_ring_empty

Lockless __ptr_ring_empty requires that consumer head is read and
written at once, atomically. Annotate accordingly to make sure compiler
does it correctly.  Switch locked callers to __ptr_ring_peek which does
not support the lockless operation.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/ptr_ring.h