Xen & SystemTap update

Xen & SystemTap update

[Stone, Joshua I]

I've recently done some more testing with SystemTap under Xen on x86_64
FC5.

It looks like 2.6.16-1.2122_FC5 on x86_64 has fixed the debuginfo
problems -- CONFIG_DEBUG_INFO is now enabled in the xen kernels and
SystemTap is able to get proper debug information.  William previously
pointed me to a Redhat bugzilla covering this point, which can probably
be resolved now:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=185662

CONFIG_KPROBES is still not enabled in the distributed xen kernels, but
I was able to build my own kernels with kprobes turned on.  Pretty much
everything seems to work as expected, except for a few failures listed
below:

xen0:
FAIL: ./systemtap.base/timers.stp shutdown (eof)  [1]
./systemtap.maps/pmap_agg_overflow.exp hangs  [1]
./systemtap.syscall/test.exp has errors  [2]

xenU:
FAIL: ./systemtap.base/kmodule.stp compilation  [3]
FAIL: ./systemtap.base/timers.stp shutdown (eof)  [1]
./systemtap.maps/pmap_agg_overflow.exp hangs  [1]
./systemtap.syscall/test.exp has errors  [2]

[1] timer.profile doesn't work on Xen, as previously noted.

[2] Fails to compile sys.stp:
semantic error: no match for probe point
while: resolving probe point kernel.function("sys_ftruncate64")
semantic error: no match for probe point
while: resolving probe point kernel.function("sys_truncate64")
semantic error: no match for probe point
while: resolving probe point kernel.function("sys_ftruncate64").return
semantic error: no match for probe point
while: resolving probe point kernel.function("sys_truncate64").return

[3] 'ext3' is built directly into the xenU kernel, not as a module.


Josh