[libvirt] [PATCH 2/2] Add some DTrace/SystemTAP probes to the RPC code

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; --- daemon/libvirtd.h | 28 +--------------- src/Makefile.am | 28 +++++++++++++++-- src/internal.h | 70 ++++++++++++++++++++++++++++++++++++++++++ src/libvirt.stp | 35 +++++++++++++++++++++ src/probes.d | 7 ++++ src/rpc/virnetclient.c | 13 +++++-- src/rpc/virnetserverclient.c | 9 +++++ 7 files changed, 157 insertions(+), 33 deletions(-) create mode 100644 src/libvirt.stp create mode 100644 src/probes.d diff --git a/daemon/libvirtd.h b/daemon/libvirtd.h index 6d6460e..43f5921 100644 --- a/daemon/libvirtd.h +++ b/daemon/libvirtd.h @@ -45,32 +45,8 @@ # include "probes.h" # endif /* LIBVIRTD_PROBES_H */ -/* Systemtap 1.2 headers have a bug where they cannot handle a - * variable declared with array type. Work around this by casting all - * arguments. This is some gross use of the preprocessor because - * PROBE is a var-arg macro, but it is better than the alternative of - * making all callers to PROBE have to be aware of the issues. And - * hopefully, if we ever add a call to PROBE with other than 2 or 3 - * end arguments, you can figure out the pattern to extend this hack. - */ -# define VIR_COUNT_ARGS(...) VIR_ARG5(__VA_ARGS__, 4, 3, 2, 1) -# define VIR_ARG5(_1, _2, _3, _4, _5, ...) _5 -# define VIR_ADD_CAST_EXPAND(a, b, ...) VIR_ADD_CAST_PASTE(a, b, __VA_ARGS__) -# define VIR_ADD_CAST_PASTE(a, b, ...) a##b(__VA_ARGS__) - -/* 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_CAST(a) ((void *)(intptr_t)(a)) -# define VIR_ADD_CAST2(a, b) \ - VIR_ADD_CAST(a), VIR_ADD_CAST(b) -# define VIR_ADD_CAST3(a, b, c) \ - VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c) - -# define VIR_ADD_CASTS(...) \ - VIR_ADD_CAST_EXPAND(VIR_ADD_CAST, VIR_COUNT_ARGS(__VA_ARGS__), \ - __VA_ARGS__) +# undef PROBE_EXPAND +# undef PROBE # define PROBE_EXPAND(NAME, ARGS) NAME(ARGS) # define PROBE(NAME, FMT, ...) \ diff --git a/src/Makefile.am b/src/Makefile.am index 7281802..d974904 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -25,6 +25,9 @@ AM_LDFLAGS = $(COVERAGE_LDFLAGS) EXTRA_DIST = $(conf_DATA) util/keymaps.csv BUILT_SOURCES = +CLEANFILES = +DISTCLEANFILES = +MAINTAINERCLEANFILES = if WITH_NETWORK UUID=$(shell uuidgen 2>/dev/null) @@ -1248,6 +1251,25 @@ libvirt_la_CFLAGS = -DIN_LIBVIRT $(AM_CFLAGS) # picked out for us. libvirt_la_DEPENDENCIES = $(libvirt_la_BUILT_LIBADD) $(LIBVIRT_SYMBOL_FILE) +if WITH_DTRACE +libvirt_la_LIBADD += probes.o +nodist_libvirt_la_SOURCES = probes.h + +BUILT_SOURCES += probes.h + +tapsetdir = $(datadir)/systemtap/tapset +tapset_DATA = libvirt.stp + +probes.h: probes.d + $(AM_V_GEN)$(DTRACE) -o $@ -h -s $< + +probes.o: probes.d + $(AM_V_GEN)$(DTRACE) -o $@ -G -s $< + +CLEANFILES += probes.h probes.o +endif + + # Create an automake "convenience library" version of libvirt_la, # just for testing, since the test harness requires access to internal # bits and pieces that we don't want to make publicly accessible. @@ -1549,6 +1571,6 @@ if WITH_NETWORK endif rmdir "$(DESTDIR)$(localstatedir)/lib/libvirt" ||: -CLEANFILES = *.gcov .libs/*.gcda .libs/*.gcno *.gcno *.gcda *.i *.s -DISTCLEANFILES = $(GENERATED_SYM_FILES) -MAINTAINERCLEANFILES = $(REMOTE_DRIVER_GENERATED) $(VIR_NET_RPC_GENERATED) $(ESX_DRIVER_GENERATED) +CLEANFILES += *.gcov .libs/*.gcda .libs/*.gcno *.gcno *.gcda *.i *.s +DISTCLEANFILES += $(GENERATED_SYM_FILES) +MAINTAINERCLEANFILES += $(REMOTE_DRIVER_GENERATED) $(VIR_NET_RPC_GENERATED) $(ESX_DRIVER_GENERATED) diff --git a/src/internal.h b/src/internal.h index 1997031..18867fd 100644 --- a/src/internal.h +++ b/src/internal.h @@ -242,4 +242,74 @@ /* divide value by size, rounding up */ # define VIR_DIV_UP(value, size) (((value) + (size) - 1) / (size)) + +# if WITH_DTRACE +# ifndef LIBVIRT_PROBES_H +# define LIBVIRT_PROBES_H +# include "probes.h" +# endif /* LIBVIRT_PROBES_H */ + +/* Systemtap 1.2 headers have a bug where they cannot handle a + * variable declared with array type. Work around this by casting all + * arguments. This is some gross use of the preprocessor because + * PROBE is a var-arg macro, but it is better than the alternative of + * making all callers to PROBE have to be aware of the issues. And + * hopefully, if we ever add a call to PROBE with other than 2 or 3 + * end arguments, you can figure out the pattern to extend this hack. + */ +# define VIR_COUNT_ARGS(...) VIR_ARG9(__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1) +# define VIR_ARG9(_1, _2, _3, _4, _5, _6, _7, _8, _9, ...) _9 +# define VIR_ADD_CAST_EXPAND(a, b, ...) VIR_ADD_CAST_PASTE(a, b, __VA_ARGS__) +# define VIR_ADD_CAST_PASTE(a, b, ...) a##b(__VA_ARGS__) + +/* 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_CAST(a) ((void *)(intptr_t)(a)) +# define VIR_ADD_CAST2(a, b) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b) +# define VIR_ADD_CAST3(a, b, c) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c) +# define VIR_ADD_CAST4(a, b, c, d) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d) +# define VIR_ADD_CAST5(a, b, c, d, e) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d), VIR_ADD_CAST(e) +# define VIR_ADD_CAST6(a, b, c, d, e, f) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d), VIR_ADD_CAST(e), VIR_ADD_CAST(f) +# define VIR_ADD_CAST7(a, b, c, d, e, f, g) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d), VIR_ADD_CAST(e), VIR_ADD_CAST(f), \ + VIR_ADD_CAST(g) +# define VIR_ADD_CAST8(a, b, c, d, e, f, g, h) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d), VIR_ADD_CAST(e), VIR_ADD_CAST(f), \ + VIR_ADD_CAST(g), VIR_ADD_CAST(h) +# define VIR_ADD_CAST9(a, b, c, d, e, f, g, h, i) \ + VIR_ADD_CAST(a), VIR_ADD_CAST(b), VIR_ADD_CAST(c), \ + VIR_ADD_CAST(d), VIR_ADD_CAST(e), VIR_ADD_CAST(f), \ + VIR_ADD_CAST(g), VIR_ADD_CAST(h), VIR_ADD_CAST(i) + +# define VIR_ADD_CASTS(...) \ + VIR_ADD_CAST_EXPAND(VIR_ADD_CAST, VIR_COUNT_ARGS(__VA_ARGS__), \ + __VA_ARGS__) + +# define PROBE_EXPAND(NAME, ARGS) NAME(ARGS) +# define PROBE(NAME, FMT, ...) \ + VIR_DEBUG_INT("trace." __FILE__ , __func__, __LINE__, \ + #NAME ": " FMT, __VA_ARGS__); \ + if (LIBVIRT_ ## NAME ## _ENABLED()) { \ + PROBE_EXPAND(LIBVIRT_ ## NAME, \ + VIR_ADD_CASTS(__VA_ARGS__)); \ + } +# else +# define PROBE(NAME, FMT, ...) \ + VIR_DEBUG_INT("trace." __FILE__, __func__, __LINE__, \ + #NAME ": " FMT, __VA_ARGS__); +# endif + + #endif /* __VIR_INTERNAL_H__ */ diff --git a/src/libvirt.stp b/src/libvirt.stp new file mode 100644 index 0000000..0b8ad14 --- /dev/null +++ b/src/libvirt.stp @@ -0,0 +1,35 @@ +probe libvirt.rpc.server_msg_tx = process("libvirt.so").mark("rpc_server_msg_tx") { + prog = $arg1; + vers = $arg2; + proc = $arg3; + type = $arg4; + status = $arg5; + serial = $arg6; +} + +probe libvirt.rpc.server_msg_rx = process("libvirt.so").mark("rpc_server_msg_rx") { + prog = $arg1; + vers = $arg2; + proc = $arg3; + type = $arg4; + status = $arg5; + serial = $arg6; +} + +probe libvirt.rpc.client_msg_tx = process("libvirt.so").mark("rpc_client_msg_tx") { + prog = $arg1; + vers = $arg2; + proc = $arg3; + type = $arg4; + status = $arg5; + serial = $arg6; +} + +probe libvirt.rpc.client_msg_rx = process("libvirt.so").mark("rpc_client_msg_rx") { + prog = $arg1; + vers = $arg2; + proc = $arg3; + type = $arg4; + status = $arg5; + serial = $arg6; +} diff --git a/src/probes.d b/src/probes.d new file mode 100644 index 0000000..e1f4212 --- /dev/null +++ b/src/probes.d @@ -0,0 +1,7 @@ +provider libvirt { + probe rpc_server_msg_tx(int prog, int vers, int proc, int type, int status, int serial); + probe rpc_server_msg_rx(int prog, int vers, int proc, int type, int status, int serial); + + probe rpc_client_msg_tx(int prog, int vers, int proc, int type, int status, int serial); + probe rpc_client_msg_rx(int prog, int vers, int proc, int type, int status, int serial); +}; diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index 64f1075..3d81f3c 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -834,10 +834,10 @@ virNetClientCallDispatch(virNetClientPtr client) if (virNetMessageDecodeHeader(&client->msg) < 0) return -1; - VIR_DEBUG("Incoming message prog %d vers %d proc %d type %d status %d serial %d", - client->msg.header.prog, client->msg.header.vers, - client->msg.header.proc, client->msg.header.type, - client->msg.header.status, client->msg.header.serial); + PROBE(RPC_CLIENT_MSG_RX, + "prog=%u vers=%u proc=%u type=%u status=%u serial=%u", + client->msg.header.prog, client->msg.header.vers, client->msg.header.proc, + client->msg.header.type, client->msg.header.status, client->msg.header.serial); if (virKeepAliveCheckMessage(client->keepalive, &client->msg)) return 0; @@ -1406,6 +1406,11 @@ virNetClientSendInternal(virNetClientPtr client, virNetClientCallPtr call; int ret = -1; + PROBE(RPC_CLIENT_MSG_TX, + "prog=%u vers=%u proc=%u type=%u status=%u serial=%u", + msg->header.prog, msg->header.vers, msg->header.proc, + msg->header.type, msg->header.status, msg->header.serial); + if (expectReply && (msg->bufferLength != 0) && (msg->header.status == VIR_NET_CONTINUE || dontBlock)) { diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c index 9bd8914..7474ea3 100644 --- a/src/rpc/virnetserverclient.c +++ b/src/rpc/virnetserverclient.c @@ -807,6 +807,11 @@ readmore: return; } + PROBE(RPC_SERVER_MSG_RX, + "prog=%u vers=%u proc=%u type=%u status=%u serial=%u", + msg->header.prog, msg->header.vers, msg->header.proc, + msg->header.type, msg->header.status, msg->header.serial); + /* Maybe send off for queue against a filter */ filter = client->filters; while (filter) { @@ -1015,6 +1020,10 @@ int virNetServerClientSendMessage(virNetServerClientPtr client, virNetServerClientLock(client); if (client->sock && !client->wantClose) { + PROBE(RPC_SERVER_MSG_TX, + "prog=%u vers=%u proc=%u type=%u status=%u serial=%u", + msg->header.prog, msg->header.vers, msg->header.proc, + msg->header.type, msg->header.status, msg->header.serial); virNetMessageQueuePush(&client->tx, msg); virNetServerClientUpdateEvent(client); -- 1.7.6.2