* Dom0 lttd-xen process
-Does an hypercall to map the buffers.
+Does an hypercall to map the buffers (increment refcount)
Does an hypercall to poll for data, put to sleep by the OS.
Uses write from the mapped buffers to a file.
+unmap buffer, decrement refcount.
* Xen
tb_control (hypercalls seen from dom0 OS)
+(hypercalls done by lttctl-xen)
- trace_create
Map a page for control information, return it for mapping by user space. (rw)
Map multiple pages for buffers. return them for mapping by user space.
(shared, read-only for consumer)
+increment refcount
- trace_start
Activate tracing in control information.
- trace_stop
for_each_domain( d )
for_each_vcpu( d, v )
vcpu_sleep_sync(v);
-destroy the channels
+decrement refcount : destroy the channels
Events coming from xen :
- Buffer switch
through virq sent to dom0
-
+- wakes up poll on the buffers FD.
* Dom0 Linux OS