X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=ltt%2Fbranches%2Fpoly%2Fdoc%2Fdeveloper%2Flttng-xen.txt;h=83a8066b4f3b422aa8dcbf45e40dd90a157c67cc;hb=1bb8d3a57d6b5b26c696d8132e809763f371aa43;hp=0c26a4bf0bdad66486b0f6190b3f4682e0eb6e84;hpb=04981608c539db32f897e06781aa497cd1d34446;p=lttv.git diff --git a/ltt/branches/poly/doc/developer/lttng-xen.txt b/ltt/branches/poly/doc/developer/lttng-xen.txt index 0c26a4bf..83a8066b 100644 --- a/ltt/branches/poly/doc/developer/lttng-xen.txt +++ b/ltt/branches/poly/doc/developer/lttng-xen.txt @@ -22,18 +22,21 @@ Reader uses poll()-like mechanism instead of polling the buffers each 100ms. * 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 @@ -47,7 +50,7 @@ Quiescent state detection. 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