Do not call vm_page_lookup() from the ddb routine, namely from "show vmopag" implementation. The vm_page_lookup() code modifies splay tree of the object pages, and asserts that object lock is taken. First issue could cause kernel data corruption, and second one instantly panics the INVARIANTS-enabled kernel.
Do not call vm_page_lookup() from the ddb routine, namely from "show
vmopag" implementation. The vm_page_lookup() code modifies splay tree
of the object pages, and asserts that object lock is taken. First issue
could cause kernel data corruption, and second one instantly panics the
INVARIANTS-enabled kernel.

Take the advantage of the fact that object->memq is ordered by page index,
and iterate over memq to calculate the runs.

While there, make the code slightly more style-compliant by moving
variables declarations to the right place.

Discussed with:	jhb, alc
Reviewed by:	alc
MFC after:	2 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase