Module Name: src
Committed By: cherry
Date: Sun Nov 25 07:48:47 UTC 2012
Modified Files:
src/sys/arch/xen/xen: evtchn.c
Log Message:
hypervisor_set_ipending() should not set the pending flag across cpus. The
reason for this is that the pending flag update is not atomic, or protected by
a lock. Since its current (mis)use in evtchn_do_event() across cpus is to
notify the remote cpu of an interrupt, we use hypervisor_send_event() instead,
to trigger an event on the remote cpu, which in turn invokes evtchn_do_event()
on that cpu and DTRT on it.
On the local cpu, we protect hypervisor_set_ipending() from re-entry via cli().
Remove a redundant and unprotected call to hypervisor_set_ipending().
Thanks to jym@ for spotting this discrepancy while reviewing a related patch.
See: http://mail-index.netbsd.org/tech-kern/2012/11/12/msg014374.html
To generate a diff of this commit:
cvs rdiff -u -r1.62 -r1.63 src/sys/arch/xen/xen/evtchn.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
