2007-11-09 Masami Hiramatsu <mhiramat@redhat.com>

        PR3858
        * print.c: Add -DRELAY_HOST=<hostname> and -DRELAY_GUEST=<hostname>
        options support.
        (_stp_print_flush): Disable irqs if -DRELAY_* option is specified.
        * print_old.c: Export stp_print_flush to other modules if the
        -DRELAY_HOST option is specified.
        * print_new.c: Ditto.
        * transport.c (_stp_transport_init): Reduce relay buffer size to
        64KB*2 if -DRELAY_GUEST is specified.
        * systemtap.printf/sharedbuf.exp: New test for buffer sharing option.
        * systemtap.printf/sharedbuf.stp: Ditto.
        * systemtap.printf/hello.stp: Ditto.
        * systemtap.printf/hello2.stp: Ditto.

6 files changed, 59 insertions, 4 deletions

diff --git a/runtime/ChangeLog b/runtime/ChangeLog
index 75272aa0..e6079bea 100644
--- a/runtime/ChangeLog
+++ b/runtime/ChangeLog
@@ -1,3 +1,13 @@
+2007-11-09  Masami Hiramatsu  <mhiramat@redhat.com>
+
+	PR3858
+	* print.c: Add -DRELAY_HOST=<hostname> and -DRELAY_GUEST=<hostname>
+	options support.
+	(_stp_print_flush): Disable irqs if -DRELAY_* option is specified.
+	* print_old.c: Export stp_print_flush to other modules if the
+	-DRELAY_HOST option is specified.
+	* print_new.c: Ditto.
+
 2007-10-25  Mike Mason <mmlnx@us.ibm.com>
 
 	* stat-common.c: Allow histogram bucket elision to be turned off
diff --git a/runtime/print.c b/runtime/print.c
index c100bbfe..326d67d5 100644
--- a/runtime/print.c
+++ b/runtime/print.c
@@ -72,6 +72,21 @@ void _stp_print_cleanup (void)
 		free_percpu(Stp_lbuf);
 }
 
+#define __DEF_EXPORT_FN(fn, postfix) fn ## _ ## postfix
+#define DEF_EXPORT_FN(fn, postfix) __DEF_EXPORT_FN(fn, postfix)
+
+#if defined(RELAY_GUEST)
+#if defined(RELAY_HOST)
+        #error "Cannot specify both RELAY_HOST and RELAY_GUEST"
+#endif
+#define EXPORT_FN(fn) DEF_EXPORT_FN(fn, RELAY_GUEST)
+#elif defined(RELAY_HOST)
+#define EXPORT_FN(fn) DEF_EXPORT_FN(fn, RELAY_HOST)
+#else /* defined(RELAY_GUEST) || defined(RELAY_HOST) */
+#define EXPORT_FN(fn) fn
+#endif
+
+#if !defined(RELAY_GUEST)
 /* The relayfs API changed between 2.6.15 and 2.6.16. */
 /* Use the appropriate print flush function. */
 
@@ -80,6 +95,26 @@ void _stp_print_cleanup (void)
 #else
 #include "print_new.c"
 #endif
+#if defined(RELAY_HOST)
+EXPORT_SYMBOL_GPL(EXPORT_FN(stp_print_flush));
+#endif
+
+#endif /*!RELAY_GUEST*/
+
+#if defined(RELAY_GUEST) || defined(RELAY_HOST)
+/* Prohibit irqs to avoid racing on a relayfs */
+extern void EXPORT_FN(stp_print_flush) (_stp_pbuf *);
+static inline void _stp_print_flush(void)
+{
+	unsigned long flags;
+	local_irq_save(flags);
+	EXPORT_FN(stp_print_flush) (per_cpu_ptr(Stp_pbuf, smp_processor_id()));
+	local_irq_restore(flags);
+}
+#else
+#define _stp_print_flush() \
+	EXPORT_FN(stp_print_flush)(per_cpu_ptr(Stp_pbuf, smp_processor_id()))
+#endif
 
 #ifndef STP_MAXBINARYARGS
 #define STP_MAXBINARYARGS 127
diff --git a/runtime/print_new.c b/runtime/print_new.c
index b34aad8a..95a83a8d 100644
--- a/runtime/print_new.c
+++ b/runtime/print_new.c
@@ -17,9 +17,8 @@
  */
 spinlock_t _stp_print_lock = SPIN_LOCK_UNLOCKED;
 
-void _stp_print_flush (void)
+void EXPORT_FN(stp_print_flush) (_stp_pbuf *pb)
 {
-	_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
 	uint32_t len = pb->len;
 
 	/* check to see if there is anything in the buffer */
diff --git a/runtime/print_old.c b/runtime/print_old.c
index 401d1af1..5ee050b5 100644
--- a/runtime/print_old.c
+++ b/runtime/print_old.c
@@ -16,9 +16,8 @@
  * @note Preemption must be disabled to use this.
  */
 
-void _stp_print_flush (void)
+void EXPORT_FN(stp_print_flush) (_stp_pbuf *pb)
 {
-	_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
 	uint32_t len = pb->len;
 
 	/* check to see if there is anything in the buffer */
diff --git a/runtime/transport/ChangeLog b/runtime/transport/ChangeLog
index ee34ef19..263a6bf8 100644
--- a/runtime/transport/ChangeLog
+++ b/runtime/transport/ChangeLog
@@ -1,3 +1,9 @@
+2007-11-09  Masami Hiramatsu  <mhiramat@redhat.com>
+
+	PR3858
+	* transport.c (_stp_transport_init): Reduce relay buffer size to
+	64KB*2 if -DRELAY_GUEST is specified.
+
 2007-11-09  Martin Hunt  <hunt@redhat.com>
 	PR 5281
 	* transport.c (_stp_detach, _stp_attach): Call utt_set_overwrite()
diff --git a/runtime/transport/transport.c b/runtime/transport/transport.c
index 9aa26b79..2904cf2f 100644
--- a/runtime/transport/transport.c
+++ b/runtime/transport/transport.c
@@ -249,6 +249,12 @@ int _stp_transport_init(void)
 	_stp_uid = current->uid;
 	_stp_gid = current->gid;
 
+#ifdef RELAY_GUEST
+        /* Guest scripts use relay only for reporting warnings and errors */
+        _stp_subbuf_size = 65536;
+        _stp_nsubbufs = 2;
+#endif
+
 	if (_stp_bufsize) {
 		unsigned size = _stp_bufsize * 1024 * 1024;
 		_stp_subbuf_size = ((size >> 2) + 1) * 65536;