evtchn_do_upcall() has a micro optimization which is depends on that xchg is a barrier.
authorkaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Fri, 30 Jun 2006 09:07:38 +0000 (10:07 +0100)
committerkaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Fri, 30 Jun 2006 09:07:38 +0000 (10:07 +0100)
commit047923da523a118caf6c3837a1205f3d3b7137d7
treefb7a77fbf7d22ef9963083e07e83ae54fc23aec1
parentff695fb354f92a11adceb627235a2d929f26cda1
evtchn_do_upcall() has a micro optimization which is depends on that xchg is a barrier.
However xchg of IA64 has acquire semantics so that event
channel notification is lost sometimes. This patch fixes it.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
linux-2.6-xen-sparse/drivers/xen/core/evtchn.c