Re: [libvirt] [PATCH 6/7] Rewrite all the DTrace/SystemTAP probing

From: "Daniel P. Berrange"<berrange(a)redhat.com> The libvirtd daemon had a few crude system tap probes. Some of these were broken during the RPC rewrite. The new modular RPC code is structured in a way that allows much more effective tracing. Instead of trying to hook up the original probes, define a new set of probes for the RPC and event code. The master probes file is now src/probes.d. This contains probes for virNetServerClientPtr, virNetClientPtr, virSocketPtr virNetTLSContextPtr and virNetTLSSessionPtr modules. Also add probes for the poll event loop. The src/dtrace2systemtap.pl script can convert the probes.d file into a libvirt_probes.stp file to make use from systemtap much simpler. The src/rpc/gensystemtap.pl script can generate a set of systemtap functions for translating RPC enum values into printable strings. This works for all RPC header enums (program, type, status, procedure) and also the authentication enum The PROBE macro will automatically generate a VIR_DEBUG statement, so any place with a PROBE can remove any existing manual DEBUG statements.

* daemon/libvirtd.stp, daemon/probes.d: Remove obsolete probing * daemon/libvirtd.h: Remove probe macros * daemon/Makefile.am: Remove all probe buildings/install * daemon/remote.c: Update authentication probes * src/dtrace2systemtap.pl, src/rpc/gensystemtap.pl: Scripts to generate STP files * src/internal.h: Add probe macros * src/probes.d: Master list of probes * src/rpc/virnetclient.c, src/rpc/virnetserverclient.c, src/rpc/virnetsocket.c, src/rpc/virnettlscontext.c, src/util/event_poll.c: Insert probe points, removing any DEBUG statements that duplicate the info --- daemon/Makefile.am | 26 +----- daemon/libvirtd.h | 47 ---------- daemon/libvirtd.stp | 65 -------------- daemon/probes.d | 12 --- daemon/remote.c | 60 ++++++++----- src/.gitignore | 4 + src/Makefile.am | 39 ++++++++- src/dtrace2systemtap.pl | 104 ++++++++++++++++++++++ src/internal.h | 73 ++++++++++++++++ src/probes.d | 72 ++++++++++++++++ src/rpc/gensystemtap.pl | 195 ++++++++++++++++++++++++++++++++++++++++++ src/rpc/virnetclient.c | 28 +++++-- src/rpc/virnetserverclient.c | 23 +++++- src/rpc/virnetsocket.c | 13 +++- src/rpc/virnettlscontext.c | 47 +++++++--- src/util/event_poll.c | 47 ++++++++--- 16 files changed, 644 insertions(+), 211 deletions(-) delete mode 100644 daemon/libvirtd.stp delete mode 100644 daemon/probes.d create mode 100644 src/dtrace2systemtap.pl create mode 100644 src/probes.d create mode 100644 src/rpc/gensystemtap.pl

diff --git a/src/.gitignore b/src/.gitignore index a619643..64e6aec 100644 --- a/src/.gitignore +++ b/src/.gitignore @@ -16,3 +16,7 @@ libvirt_qemu.def *.s remote_protocol-structs-t virt-aa-helper +libvirt_functions.stp +libvirt_probes.stp +probes.o +probes.h

+ +libvirt_functions.stp: $(wildcard */*.x) $(srcdir)/rpc/gensystemtap.pl + $(AM_V_GEN)perl -w $(srcdir)/rpc/gensystemtap.pl $(wildcard */*.x)> $@

+/* The double cast is necessary to silence gcc warnings; any pointer + * can safely go to intptr_t and back to void *, which collapses + * arrays into pointers; while any integer can be widened to intptr_t + * then cast to void *. */ +# define VIR_ADD_CASTXXXX(a) ((void *)(intptr_t)(a)) +# define VIR_ADD_CAST(a) (a)

diff --git a/src/rpc/gensystemtap.pl b/src/rpc/gensystemtap.pl new file mode 100644