Merge branch 'master' of ssh://sources.redhat.com/git/systemtap

9 files changed, 702 insertions, 152 deletions

diff --git a/dwflpp.cxx b/dwflpp.cxx
index 0c45eb7d..fbfe3f94 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -2748,7 +2748,7 @@ dwflpp::get_cfa_ops (Dwarf_Addr pc)
       if (sess.verbose > 3)
 	clog << "got dwarf cfi bias: 0x" << hex << bias << dec << endl;
       Dwarf_Frame *frame = NULL;
-      if (dwarf_cfi_addrframe (cfi, pc - bias, &frame) == 0)
+      if (dwarf_cfi_addrframe (cfi, pc, &frame) == 0)
 	dwarf_frame_cfa (frame, &cfa_ops, &cfa_nops);
       else if (sess.verbose > 3)
 	clog << "dwarf_cfi_addrframe failed: " << dwarf_errmsg(-1) << endl;
@@ -2764,7 +2764,7 @@ dwflpp::get_cfa_ops (Dwarf_Addr pc)
 	  if (sess.verbose > 3)
 	    clog << "got eh cfi bias: 0x" << hex << bias << dec << endl;
 	  Dwarf_Frame *frame = NULL;
-	  if (dwarf_cfi_addrframe (cfi, pc - bias, &frame) == 0)
+	  if (dwarf_cfi_addrframe (cfi, pc, &frame) == 0)
 	    dwarf_frame_cfa (frame, &cfa_ops, &cfa_nops);
 	  else if (sess.verbose > 3)
 	    clog << "dwarf_cfi_addrframe failed: " << dwarf_errmsg(-1) << endl;
diff --git a/man/stapprobes.irq.3stap b/man/stapprobes.irq.3stap
new file mode 100644
index 00000000..b5315c86
--- /dev/null
+++ b/man/stapprobes.irq.3stap
@@ -0,0 +1,155 @@
+.\" -*- nroff -*-
+.TH STAPPROBES.SNMP 3stap 2009-05-11 "IBM"
+.SH NAME
+stapprobes.irq \- Systemtap probes for IRQ, workqueue,etc
+
+.\" macros
+.de SAMPLE
+.br
+.RS
+.nf
+.nh
+..
+.de ESAMPLE
+.hy
+.fi
+.RE
+..
+
+.SH DESCRIPTION
+
+Probe points for probing irq handler execution, softirqs, workqueues,etc
+
+.P
+.TP
+.B workqueue.create
+probes creation of a new workqueue
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I cpu
+   cpu for which the worker thread is created.
+
+.P
+.TP
+.B workqueue.insert
+probes queuing of work on a workqueue.
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I work
+   work_struct* being executed.
+.I work_func
+   pointer to handler func.
+
+.P
+.TP
+.B workqueue.execute
+probes execution of deferred work.
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I work
+   work_struct* being executed.
+.I work_func
+   pointer to handler func.
+
+.P
+.TP
+.B workqueue.destroy
+probes destruction of each worker thread of each cpu for a workqueue.
+
+.B Arguments:
+.I wq_thread
+  task_struct of the workqueue thread.
+
+.P
+.TP
+.B irq_handler.entry
+Fires prior to execution of interrupt handler.
+.B Arguments:
+.I irq
+   irq number
+.I action
+   struct irqaction* for this interrupt number
+.I handler
+   interrupt handler function
+.I flags
+   flags for this irq.
+.I flags_str
+   A formatted string of flags.
+.I dev_name
+   name of device
+.I dev_id
+   cookie to identify device
+.I next_irqaction
+   pointer to next irqaction for shared interrupts
+.I dir
+   pointer to the /proc/irq/NN/name entry
+.I thread_fn
+   interrupt handler function for threaded interrupts
+.I thread
+   thread pointer for threaded interrupts
+.I thread_flags
+   flags related to thread
+
+.P
+.TP
+.B irq_handler.exit
+Fires post execution of interrupt handler.
+.B Arguments:
+.I irq
+   irq number
+.I action
+   struct irqaction* for this interrupt number
+.I ret
+   return value from interrupt handler that just executed.
+.I handler
+   interrupt handler function
+.I flags
+   flags for this irq.
+.I flags_str
+   A formatted string of flags.
+.I dev_name
+   name of device
+.I dev_id
+   cookie to identify device
+.I next_irqaction
+   pointer to next irqaction for shared interrupts
+.I dir
+.I thread_fn
+   interrupt handler function for threaded interrupts
+.I thread
+   thread pointer for threaded interrupts
+.I thread_flags
+   flags related to thread
+
+.P
+.TP
+.B softirq.entry
+triggered just before executing handler for a pending softirq
+.I h
+   struct softirq* for current pending softirq.
+.I vec
+   softirq_action vector
+.I action
+   pointer to softirq handler just about to execute.
+
+.P
+.TP
+.B softirq.exit
+triggered just after executing handler for a pending softirq
+.I h
+   struct softirq* for just executed softirq.
+.I vec
+   softirq_action vector
+.I action
+   pointer to softirq handler that just finished execution.
+
+.SH SEE ALSO
+.IR stap (1),
+.IR stapprobes (3stap)
+
diff --git a/man/stapprobes.irq.3stap.in b/man/stapprobes.irq.3stap.in
new file mode 100644
index 00000000..84eaab16
--- /dev/null
+++ b/man/stapprobes.irq.3stap.in
@@ -0,0 +1,155 @@
+.\" -*- nroff -*-
+.TH STAPPROBES.SNMP 3stap @DATE@ "IBM"
+.SH NAME
+stapprobes.irq \- Systemtap probes for IRQ, workqueue,etc
+
+.\" macros
+.de SAMPLE
+.br
+.RS
+.nf
+.nh
+..
+.de ESAMPLE
+.hy
+.fi
+.RE
+..
+
+.SH DESCRIPTION
+
+Probe points for probing irq handler execution, softirqs, workqueues,etc
+
+.P
+.TP
+.B workqueue.create
+probes creation of a new workqueue
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I cpu
+   cpu for which the worker thread is created.
+
+.P
+.TP
+.B workqueue.insert
+probes queuing of work on a workqueue.
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I work
+   work_struct* being executed.
+.I work_func
+   pointer to handler func.
+
+.P
+.TP
+.B workqueue.execute
+probes execution of deferred work.
+
+.B Arguments:
+.I wq_thread
+   task_struct of the workqueue thread.
+.I work
+   work_struct* being executed.
+.I work_func
+   pointer to handler func.
+
+.P
+.TP
+.B workqueue.destroy
+probes destruction of each worker thread of each cpu for a workqueue.
+
+.B Arguments:
+.I wq_thread
+  task_struct of the workqueue thread.
+
+.P
+.TP
+.B irq_handler.entry
+Fires prior to execution of interrupt handler.
+.B Arguments:
+.I irq
+   irq number
+.I action
+   struct irqaction* for this interrupt number
+.I handler
+   interrupt handler function
+.I flags
+   flags for this irq.
+.I flags_str
+   A formatted string of flags.
+.I dev_name
+   name of device
+.I dev_id
+   cookie to identify device
+.I next_irqaction
+   pointer to next irqaction for shared interrupts
+.I dir
+   pointer to the /proc/irq/NN/name entry
+.I thread_fn
+   interrupt handler function for threaded interrupts
+.I thread
+   thread pointer for threaded interrupts
+.I thread_flags
+   flags related to thread
+
+.P
+.TP
+.B irq_handler.exit
+Fires post execution of interrupt handler.
+.B Arguments:
+.I irq
+   irq number
+.I action
+   struct irqaction* for this interrupt number
+.I ret
+   return value from interrupt handler that just executed.
+.I handler
+   interrupt handler function
+.I flags
+   flags for this irq.
+.I flags_str
+   A formatted string of flags.
+.I dev_name
+   name of device
+.I dev_id
+   cookie to identify device
+.I next_irqaction
+   pointer to next irqaction for shared interrupts
+.I dir
+   pointer to the /proc/irq/NN/name entry
+.I thread_fn
+   interrupt handler function for threaded interrupts
+.I thread
+   thread pointer for threaded interrupts
+.I thread_flags
+   flags related to thread
+
+.P
+.TP
+.B softirq.entry
+triggered just before executing handler for a pending softirq
+.I h
+   struct softirq* for current pending softirq.
+.I vec
+   softirq_action vector
+.I action
+   pointer to softirq handler just about to execute.
+
+.P
+.TP
+.B softirq.exit
+triggered just after executing handler for a pending softirq
+.I h
+   struct softirq* for just executed softirq.
+.I vec
+   softirq_action vector
+.I action
+   pointer to softirq handler that just finished execution.
+
+.SH SEE ALSO
+.IR stap (1),
+.IR stapprobes (3stap)
diff --git a/runtime/runtime.h b/runtime/runtime.h
index a95627ae..ba583aeb 100644
--- a/runtime/runtime.h
+++ b/runtime/runtime.h
@@ -179,6 +179,17 @@ void cleanup_module(void)
   _stp_transport_close();
 }
 
+#define pseudo_atomic_cmpxchg(v, old, new) ({\
+	int ret;\
+	unsigned long flags;\
+	local_irq_save(flags);\
+	ret = atomic_read(v);\
+	if (likely(ret == old))\
+		atomic_set(v, new);\
+	local_irq_restore(flags);\
+	ret; })
+
+
 MODULE_LICENSE("GPL");
 
 #endif /* _RUNTIME_H_ */
diff --git a/tapset/irq.stp b/tapset/irq.stp
new file mode 100644
index 00000000..6a9b9147
--- /dev/null
+++ b/tapset/irq.stp
@@ -0,0 +1,172 @@
+/*
+ *      Copyright (C) 2009 IBM Corp.
+ *      This file is part of systemtap, and is free software.  You can
+ *      redistribute it and/or modify it under the terms of the GNU General
+ *      Public License (GPL); either version 2, or (at your option) any
+ *      later version.
+ *
+ *      Version 1.0     prerna@linux.vnet.ibm.com     2009-10-28
+ *
+ * Tracepoint based tapset for IRQs, Workqueues, etc
+ *
+ */
+// Probes for workqueues.
+
+/**
+ * probe workqueue.create : probes creation of a new workqueue
+ * @wq_thread : task_struct of the workqueue thread.
+ * @cpu	  : cpu for which the worker thread is created.
+ */
+probe workqueue.create = kernel.trace("workqueue_creation")
+{
+	wq_thread = $wq_thread
+	cpu = $cpu
+}
+
+/**
+ * probe workqueue.insert : probes queuing of work on a workqueue
+ * @wq_thread : task_struct of the workqueue thread.
+ * @work : work_struct* being queued.
+ * @work_func :	pointer to handler func.
+ */
+probe workqueue.insert = kernel.trace("workqueue_insertion")
+{
+	wq_thread = $wq_thread
+	work = $work
+	work_func = $work->func
+}
+
+/**
+ * probe workqueue.execute : probes execution of deferred work.
+ * @wq_thread :	task_struct of the workqueue thread.
+ * @work : work_struct* being executed.
+ * @work_func :	pointer to handler func.
+ */
+probe workqueue.execute = kernel.trace("workqueue_execution")
+{
+	wq_thread = $wq_thread
+	work = $work
+	work_func = $work->func
+}
+
+/**
+ * probe workqueue.destroy : probes destruction of each worker thread of each cpu for a workqueue.
+ * @wq_thread : task_struct of the workqueue thread.
+ */
+probe workqueue.destroy = kernel.trace("workqueue_destruction")
+{
+	wq_thread = $wq_thread
+}
+
+// Probes for IRQ handlers.
+
+/**
+ * probe irq_handler.entry : Fires prior to execution of interrupt handler.
+ * @irq	: irq number.
+ * @action : struct irqaction* for this interrupt num.
+ * @handler : interrupt handler function.
+ * @flags : Flags for IRQ handler
+ *			IRQF_DISABLED [0x00000020]	: keep irqs disabled when calling action handler.
+ *			IRQF_SAMPLE_RANDOM [0x00000040]	: irq is used to feed the random generator
+ *			IRQF_SHARED [0x00000080]	: allow sharing the irq among several devices
+ *			IRQF_PROBE_SHARED [0x00000100]	: set by callers when they expect sharing mismatches to occur
+ *			IRQF_TIMER [0x00000200]		: Flag to mark this interrupt as timer interrupt
+ *			IRQF_PERCPU [0x00000400]	: Interrupt is per cpu.
+ *			IRQF_NOBALANCING [0x00000800]	: Flag to exclude this interrupt from irq balancing
+ *			IRQF_IRQPOLL [0x00001000]	: Interrupt is used for polling.
+ *			IRQF_ONESHOT [0x00002000]	: Interrupt is not reenabled after the hardirq handler finished.
+ * @flags_str : symbolic string representation of IRQ flags.
+ * @dev_name : name of device.
+ * @dev_id : Cookie to identify device.
+ * @next_irqaction : pointer to next irqaction for shared interrupts.
+ * @dir	: pointer to the proc/irq/NN/name entry
+ * @thread_fn : interupt handler function for threaded interrupts.
+ * @thread : thread pointer for threaded interrupts.
+ * @thread_flags : Flags related to thread.
+ */
+probe irq_handler.entry = kernel.trace("irq_handler_entry")
+{
+	irq = $irq
+	action = $action
+	handler = $action->handler
+	flags = $action->flags
+	flags_str = irqflags_str(flags)
+	dev_name = $action->name
+	dev_id = $action->dev_id
+	next_irqaction = $action->next
+	dir = $action->dir
+	thread_fn = $action->thread_fn
+	thread = $action->thread
+	thread_flags = $action->thread_flags
+}
+
+/**
+ * probe irq_handler.exit : Fires just after execution of interrupt handler.
+ * @irq : interrupt number
+ * @action : struct irqaction*
+ * @ret	: return value of the handler
+ * @handler : interrupt handler function that was executed.
+ * @flags : flags for IRQ handler
+ *			IRQF_DISABLED	[0x00000020]	: keep irqs disabled when calling action handler.
+ *			IRQF_SAMPLE_RANDOM [0x00000040]	: irq is used to feed the random generator
+ *			IRQF_SHARED [0x00000080]	: allow sharing the irq among several devices
+ *			IRQF_PROBE_SHARED [0x00000100]	: set by callers when they expect sharing mismatches to occur
+ *			IRQF_TIMER [0x00000200]		: Flag to mark this interrupt as timer interrupt
+ *			IRQF_PERCPU [0x00000400]	: Interrupt is per cpu.
+ *			IRQF_NOBALANCING [0x00000800]	: Flag to exclude this interrupt from irq balancing
+ *			IRQF_IRQPOLL [0x00001000]	: Interrupt is used for polling.
+ *			IRQF_ONESHOT [0x00002000]	: Interrupt is not reenabled after the hardirq handler finished.
+ * @flags_str : symbolic string representation of IRQ flags.
+ * @dev_name : name of device.
+ * @dev_id : Cookie to identify device.
+ * @next_irqaction : pointer to next irqaction for shared interrupts.
+ * @dir	: pointer to the proc/irq/NN/name entry
+ * @thread_fn : interupt handler function for threaded interrupts.
+ * @thread : thread pointer for threaded interrupts.
+ * @thread_flags : Flags related to thread.
+ */
+probe irq_handler.exit = kernel.trace("irq_handler_exit")
+{
+	irq = $irq
+	action = $action
+	ret = $ret
+	handler = $action->handler
+	flags = $action->flags
+	flags_str = irqflags_str(flags)
+	dev_name = $action->name
+	dev_id = $action->dev_id
+	next_irqaction = $action->next
+	dir = $action->dir
+	thread_fn = $action->thread_fn
+	thread = $action->thread
+	thread_flags = $action->thread_flags
+}
+
+// Softirq based probes.
+/**
+ * probe softirq.entry 	: triggered just before executing handler
+ *			  for a pending softirq.
+ * @h : struct softirq_action* for current pending softirq.
+ * @vec	: softirq_action vector.
+ * @action : pointer to softirq handler just about to execute.
+ */
+probe softirq.entry = kernel.trace("softirq_entry")
+{
+	h = $h
+	vec = $vec
+	action = $h->action
+}
+
+/**
+ * probe softirq.exit 	: triggered just after executing handler for a pending
+ *			  softirq.
+ * @h : struct softirq_action* for just executed softirq.
+ * @vec	: softirq_action vector.
+ * @action : pointer to softirq handler that just finished execution.
+ */
+probe softirq.exit = kernel.trace("softirq_exit")
+{
+	h = $h
+	vec = $vec
+	action = $h->action
+}
diff --git a/tapset/nfs.stp b/tapset/nfs.stp
index 6752747f..6b7d5eeb 100644
--- a/tapset/nfs.stp
+++ b/tapset/nfs.stp
@@ -2,6 +2,7 @@
 // Copyright (C) 2006-2007 IBM Corp.
 // Copyright (C) 2007 Intel Corporation.
 // Copyright (C) 2007 Bull S.A.S
+// Copyright (c) 2009 Red Hat Inc.
 //
 // This file is part of systemtap, and is free software.  You can
 // redistribute it and/or modify it under the terms of the GNU General
@@ -13,53 +14,53 @@
 #include <linux/nfs_fs.h>
 %}
 
-/*Get cache_validity flag from struct inode*/
-function __nfsi_cache_valid:long(inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+/* Get cache_validity flag from struct inode */
+function __nfsi_cache_valid:long (inode:long) %{ /* pure */
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_inode * nfsi = NFS_I(inode);
+        struct nfs_inode *nfsi = NFS_I(inode);
         THIS->__retvalue = kread(&(nfsi->cache_validity));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get read_cache_jiffies from struct inode*/
-function __nfsi_rcache_time :long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+/* Get read_cache_jiffies from struct inode */
+function __nfsi_rcache_time:long (inode:long) %{ /* pure */
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_inode * nfsi = NFS_I(inode);
+        struct nfs_inode *nfsi = NFS_I(inode);
         THIS->__retvalue = kread(&(nfsi->read_cache_jiffies));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get attrtimeo from struct inode*/
+/* Get attrtimeo from struct inode */
 function __nfsi_attr_time :long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_inode * nfsi = NFS_I(inode);
+        struct nfs_inode *nfsi = NFS_I(inode);
         THIS->__retvalue = kread(&(nfsi->attrtimeo));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get ndirty from struct inode*/
+/* Get ndirty from struct inode */
 function __nfsi_ndirty:long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_inode * nfsi = NFS_I(inode);
+        struct nfs_inode *nfsi = NFS_I(inode);
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,22)
         THIS->__retvalue = kread(&(nfsi->ndirty));
 #else
@@ -69,24 +70,24 @@ function __nfsi_ndirty:long (inode:long) %{ /* pure */
     CATCH_DEREF_FAULT();
 %}
 
-/*Get rsize from struct inode*/
+/* Get rsize from struct inode */
 function __nfs_server_rsize:long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_server * nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
+        struct nfs_server *nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
         THIS->__retvalue = kread(&(nfs_srv->rsize));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get version from struct inode*/
+/* Get version from struct inode */
 function __nfs_version:long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
         const struct nfs_rpc_ops *rpc_ops = NFS_PROTO(inode); /* FIXME: deref hazard! */
@@ -95,47 +96,47 @@ function __nfs_version:long (inode:long) %{ /* pure */
     CATCH_DEREF_FAULT();
 %}
 
-/*Get wsize from struct inode*/
+/* Get wsize from struct inode */
 function __nfs_server_wsize:long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_server * nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
+        struct nfs_server *nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
         THIS->__retvalue = kread(&(nfs_srv->wsize));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get rpages from struct inode*/
+/* Get rpages from struct inode */
 function __nfs_rpages:long (inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_server * nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
+        struct nfs_server *nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
         THIS->__retvalue = kread(&(nfs_srv->rpages));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get wpages from struct inode*/
-function __nfs_wpages:long(inode:long) %{ /* pure */
-    struct inode * inode = (struct inode *)(long)(THIS->inode);
+/* Get wpages from struct inode */
+function __nfs_wpages:long (inode:long) %{ /* pure */
+    struct inode *inode = (struct inode *)(long)(THIS->inode);
 
-    if(inode == NULL) 
+    if (inode == NULL) 
         THIS->__retvalue = -1;
     else {
-        struct nfs_server * nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
+        struct nfs_server *nfs_srv = NFS_SERVER(inode); /* FIXME: deref hazard! */
         THIS->__retvalue = kread(&(nfs_srv->wpages));
     }
     CATCH_DEREF_FAULT();
 %}
 
-/*Get struct inode from struct page*/
-function __p2i :long(page:long)
+/* Get struct inode from struct page */
+function __p2i :long (page:long)
 {
     mapping = page? @cast(page, "page", "kernel:nfs")->mapping : 0
     if (mapping == 0)
@@ -143,7 +144,7 @@ function __p2i :long(page:long)
     return @cast(mapping, "address_space", "kernel:nfs")->host
 }
 
-/*Get i_flags from struct page*/
+/* Get i_flags from struct page */
 function __p2i_flag : long (page:long)
 {
     host = __p2i(page)
@@ -152,7 +153,7 @@ function __p2i_flag : long (page:long)
     return @cast(host, "inode", "kernel:nfs")->i_flags
 }
 
-/*Get i_state from struct page*/
+/* Get i_state from struct page */
 function __p2i_state :long (page:long)
 {
     host = __p2i(page)
@@ -161,7 +162,7 @@ function __p2i_state :long (page:long)
     return @cast(host, "inode", "kernel:nfs")->i_state
 }
 
-/*Get i_size from struct page*/
+/* Get i_size from struct page */
 function __p2i_size :long (page:long)
 {
     host = __p2i(page)
@@ -170,7 +171,7 @@ function __p2i_size :long (page:long)
     return @cast(host, "inode", "kernel:nfs")->i_size
 }
 
-/*Get s_flags from struct page*/
+/* Get s_flags from struct page */
 function __p2sb_flag:long (page:long)
 {
     host = __p2i(page)
@@ -181,7 +182,7 @@ function __p2sb_flag:long (page:long)
 }
 
 function __d_loff_t :long (ppos :long) %{ /* pure */
-    loff_t * ppos = (loff_t *) ((long)THIS->ppos);
+    loff_t *ppos = (loff_t *)((long)THIS->ppos);
 
     if (ppos == NULL)
         THIS->__retvalue = -1;
@@ -236,12 +237,14 @@ function __file_parentname:string (file:long)
  * Combination of generic_segment_checks and iov_length functions
  * @iov:        io vector request
  * @nr_segs:    number of segments in the iovec
- * @check_flag:  whether to check (0 as iov_length, 1 as generic_segment_checks)
- * @access_flags: valid when check_flag >0, type of access: VERIFY_READ - 0 or VERIFY_WRITE - 1
+ * @check_flag:  whether to check (0 as iov_length, 1 as
+ *               generic_segment_checks)
+ * @access_flags: valid when check_flag >0, type of access:
+ *                VERIFY_READ - 0 or VERIFY_WRITE - 1
  *
  * @return:      number of bytes to write/read
-*/
-function __iov_length:long(iov:long, nr_segs:long, check_flag:long, access_flags:long) %{ /* pure */
+ */
+function __iov_length:long (iov:long, nr_segs:long, check_flag:long, access_flags:long) %{ /* pure */
         unsigned long seg;
         size_t ret = 0;
         const struct iovec *iov = (const struct iovec *)(long)THIS->iov;
@@ -263,7 +266,7 @@ function __iov_length:long(iov:long, nr_segs:long, check_flag:long, access_flags
         		THIS->__retvalue = -EFAULT;
 			return;
 		}
-                ret-= iov_len;     /* This segment is no good */
+                ret -= iov_len;     /* This segment is no good */
                 break;
 	   }
 	}
@@ -301,9 +304,9 @@ probe nfs.fop.return = nfs.fop.llseek.return,
 {
 }
 
-/*probe nfs.fop.llseek
+/* probe nfs.fop.llseek
  *
- *  Fires when do a llseek operation on nfs,it probes
+ *  Fires when do a llseek operation on nfs, it probes
  *  llseek file operation of nfs
  *
  *  Arguments:
@@ -318,7 +321,7 @@ probe nfs.fop.return = nfs.fop.llseek.return,
  *         SEEK_END
  *               The offset is set to the size of the file plus offset bytes.
  *
-*/
+ */
 probe nfs.fop.llseek = kernel.function ("nfs_file_llseek") !,
                        module("nfs").function("nfs_file_llseek")
 {
@@ -341,15 +344,16 @@ probe nfs.fop.llseek.return = kernel.function ("nfs_file_llseek").return !,
         name = "nfs.fop.llseek.return"
         retstr = sprintf("%d", $return)
 }
-/*probe nfs.fop.read
+
+/* probe nfs.fop.read
  *
- * Fires when do a read operation on nfs,it probes
+ * Fires when do a read operation on nfs, it probes
  * read file operation of nfs
  * 
  * Arguments:
  *        
  *
-*/
+ */
 probe nfs.fop.read = vfs.do_sync_read
 {
 	s_id = __file_id($filp)
@@ -362,16 +366,15 @@ probe nfs.fop.read.return = vfs.do_sync_read.return
         name = "nfs.fop.read.return"
 }
 
-/*probe nfs.fop.write
+/* probe nfs.fop.write
  *
- * Fires when do a write operation on nfs,it probes
+ * Fires when do a write operation on nfs, it probes
  * write file operation of nfs
  * 
  * Arguments:
  *        
  *
-*/
-
+ */
 probe nfs.fop.write = vfs.do_sync_write
 {
 	s_id = __file_id($filp)
@@ -384,7 +387,7 @@ probe nfs.fop.write.return = vfs.do_sync_write.return
         name = "nfs.fop.write.return"
 }
 
-/*probe nfs.fop.aio_read
+/* probe nfs.fop.aio_read
  *
  * It probes aio_read file operation of nfs
  * 
@@ -403,7 +406,7 @@ probe nfs.fop.write.return = vfs.do_sync_write.return
  *   We need to revalidate the cached attrs for this inode if
  *
  *      jiffies - read_cache_jiffies > attrtimeo
-*/
+ */
 probe nfs.fop.aio_read = kernel.function ("nfs_file_read") !,
                        module("nfs").function("nfs_file_read")
 {
@@ -416,7 +419,7 @@ probe nfs.fop.aio_read = kernel.function ("nfs_file_read") !,
 
 %( kernel_v >= "2.6.19" %?
 	buf = $iov->iov_base
-        count = __iov_length($iov,$nr_segs,0,-1)
+        count = __iov_length($iov, $nr_segs, 0, -1)
 %:
         buf = $buf
         count = $count
@@ -432,7 +435,7 @@ probe nfs.fop.aio_read = kernel.function ("nfs_file_read") !,
 
 
         name = "nfs.fop.aio_read"
-        argstr = sprintf("%p,%d, %d",buf,count, pos)
+        argstr = sprintf("%p, %d, %d", buf, count, pos)
 
         size = count
         units = "bytes"
@@ -451,7 +454,7 @@ probe nfs.fop.aio_read.return = kernel.function ("nfs_file_read").return !,
         }
 }
 
-/*probe nfs.fop.aio_write
+/* probe nfs.fop.aio_write
  *
  * It probes aio_write file operation of nfs
  * 
@@ -464,7 +467,7 @@ probe nfs.fop.aio_read.return = kernel.function ("nfs_file_read").return !,
  *    parent_name : parent dir name
  *    file_name : file name
  *
-*/
+ */
 probe nfs.fop.aio_write = kernel.function("nfs_file_write") !,
                           module("nfs").function("nfs_file_write")
 {
@@ -476,7 +479,7 @@ probe nfs.fop.aio_write = kernel.function("nfs_file_write") !,
         pos = $pos
 %( kernel_v >= "2.6.19" %?
 	buf = $iov->iov_base
-        count = __iov_length($iov,$nr_segs,0,-1)
+        count = __iov_length($iov, $nr_segs, 0, -1)
 %:
         buf = $buf
         count = $count
@@ -492,7 +495,7 @@ probe nfs.fop.aio_write = kernel.function("nfs_file_write") !,
         units = "bytes"
 }
 
-probe nfs.fop.aio_write.return =  kernel.function("nfs_file_write").return !,
+probe nfs.fop.aio_write.return = kernel.function("nfs_file_write").return !,
                           module("nfs").function("nfs_file_write").return
 {
         name = "nfs.fop.aio_write.return"
@@ -504,7 +507,7 @@ probe nfs.fop.aio_write.return =  kernel.function("nfs_file_write").return !,
         }
 }
 
-/*probe nfs.fop.mmap
+/* probe nfs.fop.mmap
  *
  * Fires when do an mmap operation on nfs,
  * it probes mmap operation of nfs
@@ -525,7 +528,7 @@ probe nfs.fop.aio_write.return =  kernel.function("nfs_file_write").return !,
  *   We need to revalidate the cached attrs for this inode if
  *
  *      jiffies - read_cache_jiffies > attrtimeo
-*/
+ */
 probe nfs.fop.mmap = kernel.function("nfs_file_mmap") !,
                      module("nfs").function("nfs_file_mmap")
 {
@@ -556,7 +559,7 @@ probe nfs.fop.mmap.return = kernel.function("nfs_file_mmap").return !,
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.fop.open
+/* probe nfs.fop.open
  *
  * Fires when do an open operation on nfs,
  * it probes open file operation of nfs
@@ -567,7 +570,7 @@ probe nfs.fop.mmap.return = kernel.function("nfs_file_mmap").return !,
  *    file_name : file name
  *    flag : file flag
  *    i_size : file length in bytes 
-*/
+ */
 probe nfs.fop.open = kernel.function("nfs_file_open") !,
                      module("nfs").function("nfs_file_open")
 {
@@ -582,7 +585,7 @@ probe nfs.fop.open = kernel.function("nfs_file_open") !,
         i_size = $inode->i_size
    
         name = "nfs.fop.open"
-        argstr = sprintf("%d,%d, %s", flag, ino, filename)
+        argstr = sprintf("%d, %d, %s", flag, ino, filename)
 }
 
 probe nfs.fop.open.return = kernel.function("nfs_file_open").return !,
@@ -592,7 +595,7 @@ probe nfs.fop.open.return = kernel.function("nfs_file_open").return !,
         retstr = sprintf("%d", $return)        
 }
 
-/*probe nfs.fop.flush
+/* probe nfs.fop.flush
  *
  * Fires when do a flush file operation on nfs,
  * it probes flush file operation of nfs
@@ -602,7 +605,7 @@ probe nfs.fop.open.return = kernel.function("nfs_file_open").return !,
  *    ino : inode number        
  *    mode : file mode
  *    ndirty : number of dirty page
-*/
+ */
 probe nfs.fop.flush = kernel.function("nfs_file_flush") !,
                       module("nfs").function("nfs_file_flush")
 {
@@ -615,17 +618,17 @@ probe nfs.fop.flush = kernel.function("nfs_file_flush") !,
         ndirty = __nfsi_ndirty(__file_inode($file))
 
         name = "nfs.fop.flush"
-        argstr = sprintf("%d",ino)
+        argstr = sprintf("%d", ino)
 }
 
 probe nfs.fop.flush.return = kernel.function("nfs_file_flush").return !,
                       module("nfs").function("nfs_file_flush").return
 {
         name = "nfs.fop.flush.return"
-        retstr = sprintf("%d",$return)
+        retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.fop.release
+/* probe nfs.fop.release
  *
  * Fires when do a release page operation on nfs,
  * it probes release file operation of nfs
@@ -634,7 +637,7 @@ probe nfs.fop.flush.return = kernel.function("nfs_file_flush").return !,
  *    dev : device identifier
  *    ino : inode number        
  *    mode : file mode
-*/
+ */
 probe nfs.fop.release = kernel.function("nfs_file_release") !,
                       module("nfs").function("nfs_file_release")
 {
@@ -646,7 +649,7 @@ probe nfs.fop.release = kernel.function("nfs_file_release") !,
         mode = $filp->f_mode
 
         name = "nfs.fop.release"
-        argstr = sprintf("%d" , ino)
+        argstr = sprintf("%d", ino)
 }
 
 probe nfs.fop.release.return = kernel.function("nfs_file_release").return !,
@@ -656,7 +659,7 @@ probe nfs.fop.release.return = kernel.function("nfs_file_release").return !,
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.fop.fsync
+/* probe nfs.fop.fsync
  *
  * Fires when do a fsync operation on nfs,
  * it probes fsync file operation of nfs
@@ -665,7 +668,7 @@ probe nfs.fop.release.return = kernel.function("nfs_file_release").return !,
  *    dev : device identifier
  *    ino : inode number       
  *    ndirty : number of dirty pages 
-*/
+ */
 probe nfs.fop.fsync = kernel.function("nfs_fsync") !,
                       module("nfs").function("nfs_fsync")
 {
@@ -677,7 +680,7 @@ probe nfs.fop.fsync = kernel.function("nfs_fsync") !,
         ndirty = __nfsi_ndirty(__file_inode($file))
 
         name = "nfs.fop.fsync"
-	argstr = sprintf("%d",ino)  
+	argstr = sprintf("%d", ino)  
 }
 
 probe nfs.fop.fsync.return = kernel.function("nfs_fsync").return !,
@@ -687,7 +690,7 @@ probe nfs.fop.fsync.return = kernel.function("nfs_fsync").return !,
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.fop.lock
+/* probe nfs.fop.lock
  *
  * Fires when do a file lock operation on nfs,
  * it probes lock file operation of nfs
@@ -701,7 +704,7 @@ probe nfs.fop.fsync.return = kernel.function("nfs_fsync").return !,
  *    fl_flag : lock flags
  *    fl_start : starting offset of locked region 
  *    fl_end   : ending offset of locked region  
-*/
+ */
 probe nfs.fop.lock = kernel.function("nfs_lock") !,
                      module("nfs").function("nfs_lock")
 {
@@ -719,18 +722,17 @@ probe nfs.fop.lock = kernel.function("nfs_lock") !,
         fl_end  = $fl->fl_end
 
         name = "nfs.fop.lock"
-        argstr = sprintf("%d,%d",cmd,i_mode)
+        argstr = sprintf("%d, %d", cmd, i_mode)
 }
 
 probe nfs.fop.lock.return = kernel.function("nfs_lock").return !,
                              module("nfs").function("nfs_lock").return
 {
          name = "nfs.fop.lock.return"
-         retstr = sprintf("%d",$return)
+         retstr = sprintf("%d", $return)
 }
 
-
-/*probe nfs.fop.sendfile
+/* probe nfs.fop.sendfile
  *
  * Fires when do a send file  operation on nfs,
  * it probes sendfile file operation of nfs
@@ -747,7 +749,7 @@ probe nfs.fop.lock.return = kernel.function("nfs_lock").return !,
  *   We need to revalidate the cached attrs for this inode if
  *
  *      jiffies - read_cache_jiffies > attrtimeo
-*/
+ */
 %( kernel_v <= "2.6.18" %?
 probe nfs.fop.sendfile = kernel.function("nfs_file_sendfile") !,
                               module("nfs").function("nfs_file_sendfile")
@@ -766,7 +768,7 @@ probe nfs.fop.sendfile = kernel.function("nfs_file_sendfile") !,
         attr_time   = __nfsi_attr_time(__file_inode($filp))
 
         name = "nfs.fop.sendfile"
-        argstr = sprintf("%d,%d", count,ppos)
+        argstr = sprintf("%d, %d", count, ppos)
 
         size = count
         units = "bytes"
@@ -785,28 +787,28 @@ probe nfs.fop.sendfile.return = kernel.function("nfs_file_sendfile").return !,
 }
 %)
 
-/*probe nfs.fop.check_flags
+/* probe nfs.fop.check_flags
  *
  * Fires when do a checking flag  operation on nfs,
  * it probes check_flag file operation of nfs
  * 
  * Arguments:
  *    flag : file flag
-*/
+ */
 probe nfs.fop.check_flags =  kernel.function("nfs_check_flags") !,
                              module("nfs").function("nfs_check_flags")
 {
         flag = $flags
         
         name = "nfs.fop.check_flags"
-        argstr = sprintf("%d",flag)
+        argstr = sprintf("%d", flag)
 }
 
-probe nfs.fop.check_flags.return =  kernel.function("nfs_check_flags").return !,
+probe nfs.fop.check_flags.return = kernel.function("nfs_check_flags").return !,
                              module("nfs").function("nfs_check_flags").return
 {
         name = "nfs.fop.check_flags.return"
-        retstr = sprintf("%d",$return)
+        retstr = sprintf("%d", $return)
 }
 
 probe nfs.aop.entries = nfs.aop.readpage,
@@ -831,7 +833,7 @@ probe nfs.aop.return = nfs.aop.readpage.return,
 
 /* probe nfs.aop.readpage
  *
- *   Read the page ,only fies when a previous async
+ *   Read the page, only fies when a previous async
  *   read operation failed
  *
  * Arguments:
@@ -843,8 +845,8 @@ probe nfs.aop.return = nfs.aop.readpage.return,
  *   sb_flag : super block flags
  *   file  : file argument
  *   page_index : offset within mapping, can used a 
-                  page identifier and position identifier
-                  in the page frame
+ *                page identifier and position identifier
+ *                in the page frame
  *   rsize :  read size  (in bytes)
  *   size :  number of pages to be read in this execution 
  */
@@ -867,7 +869,7 @@ probe nfs.aop.readpage = kernel.function ("nfs_readpage") !,
         rsize = __nfs_server_rsize(__inode)
 
         name = "nfs.aop.readpage"
-        argstr = sprintf("%d,%d" , page_index,rsize)
+        argstr = sprintf("%d, %d", page_index, rsize)
 
         size = 1
         units = "pages"
@@ -885,7 +887,7 @@ probe nfs.aop.readpage.return = kernel.function ("nfs_readpage").return !,
 
 /* probe nfs.aop.readpages
  *
- * Fies when in readahead way,read several pages once
+ * Fies when in readahead way, read several pages once
  * Arguments:
  *   dev : device identifier
  *   ino : inode number   
@@ -895,7 +897,7 @@ probe nfs.aop.readpage.return = kernel.function ("nfs_readpage").return !,
  *   rsize  : read size (in bytes)
  *   size :  number of pages attempted to read in this execution 
  */
-probe nfs.aop.readpages =  kernel.function ("nfs_readpages") !,
+probe nfs.aop.readpages = kernel.function ("nfs_readpages") !,
         module("nfs").function ("nfs_readpages")
 {
         dev = $mapping->host->i_sb->s_dev
@@ -908,7 +910,7 @@ probe nfs.aop.readpages =  kernel.function ("nfs_readpages") !,
         rsize  = __nfs_server_rsize($mapping->host)
 
         name = "nfs.aop.readpages"
-        argstr = sprintf("%d" , nr_pages)
+        argstr = sprintf("%d", nr_pages)
 
         size = nr_pages
         units = "pages"
@@ -920,22 +922,22 @@ probe nfs.aop.readpages.return = kernel.function ("nfs_readpages").return !,
         name = "nfs.aop.readpages.return"
         retstr = sprintf("%d", $return)
 
-
-        if($return > 0 )
+        if ($return > 0 )
         {
             size = retstr
         }
         units = "pages"
 }
-/*probe nfs.aop.set_page_dirty
+
+/* probe nfs.aop.set_page_dirty
  *
- *   __set_page_dirty_nobuffers is used to set a page dirty,but
+ *   __set_page_dirty_nobuffers is used to set a page dirty, but
  *   not all the buffers.
  *
  *  Arguments:
  *     __page : the address of page
  *      page_flag : page flags
-*/
+ */
 probe nfs.aop.set_page_dirty =
             kernel.function ("__set_page_dirty_nobuffers") !,
              module("nfs").function ("__set_page_dirty_nobuffers")
@@ -943,12 +945,12 @@ probe nfs.aop.set_page_dirty =
  /*       dev = $mapping->host->i_sb->s_dev
         devname = __find_bdevname(dev, $mapping->host->i_sb->s_bdev)
         ino = $mapping->host->i_ino
-*/
+  */
         __page = $page
         page_flag = $page->flags
 
         name = "nfs.aop.set_page_dirty"
-        argstr = sprintf("%d",page_flag)
+        argstr = sprintf("%d", page_flag)
 }
 
 probe nfs.aop.set_page_dirty.return =
@@ -959,7 +961,7 @@ probe nfs.aop.set_page_dirty.return =
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.aop.writepage
+/* probe nfs.aop.writepage
  *
  *   Write an mapped page to the server
  *
@@ -967,20 +969,22 @@ probe nfs.aop.set_page_dirty.return =
  *     __page : the address of page
  *     dev : device identifier
  *     ino : inode number  
- *     for_reclaim : a flag of writeback_control, indicates if it's invoked from the page allocator 
- *     for_kupdate : a flag of writeback_control, indicates if it's a kupdate writeback
+ *     for_reclaim : a flag of writeback_control, indicates if it's
+ *                   invoked from the page allocator
+ *     for_kupdate : a flag of writeback_control, indicates if it's a
+ *                   kupdate writeback
  *      The priority of wb is decided by above two flags
  *     i_flag : file flags
  *     i_size : file length in bytes
  *     i_state : inode state flags
  *     sb_flag : super block flags
  *     page_index : offset within mapping, can used a 
-                    page identifier and position identifier
-                    in the page frame
+ *                  page identifier and position identifier
+ *                  in the page frame
  *     wsize :  write size
  *     size  :  number of pages to be written in this execution 
-*/
-probe nfs.aop.writepage =  kernel.function ("nfs_writepage") !,
+ */
+probe nfs.aop.writepage = kernel.function ("nfs_writepage") !,
              module("nfs").function ("nfs_writepage")
 {
         __page = $page
@@ -1004,33 +1008,36 @@ probe nfs.aop.writepage =  kernel.function ("nfs_writepage") !,
         wsize = __nfs_server_wsize(__inode)            
  
         name = "nfs.aop.writepage"
-        argstr = sprintf("%d",page_index)
+        argstr = sprintf("%d", page_index)
 
         size = 1
         units = "pages"
 }
 
-probe nfs.aop.writepage.return =  kernel.function ("nfs_writepage").return !,
+probe nfs.aop.writepage.return = kernel.function ("nfs_writepage").return !,
              module("nfs").function ("nfs_writepage").return
 {
         name = "nfs.aop.writepage.return"
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.aop.writepages
+/* probe nfs.aop.writepages
  *  Write several dirty pages to the serve
  *Arguments:
  *     dev : device identifier
  *     ino : inode number  
- *     for_reclaim : a flag of writeback_control, indicates if it's invoked from the page allocator 
- *     for_kupdate : a flag of writeback_control, indicates if it's a kupdate writeback
+ *     for_reclaim : a flag of writeback_control, indicates if it's
+ *                   invoked from the page allocator
+ *     for_kupdate : a flag of writeback_control, indicates if it's a
+ *                   kupdate writeback
  *      The priority of wb is decided by above two flags
  *      wsize :  write size
  *      wpages : write size (in pages)
- *      nr_to_write : number of pages attempted to be written in this execution  
+ *      nr_to_write : number of pages attempted to be written in this
+ *                    execution
  *      size : number of pages attempted to be written in this execution  
-*/
-probe nfs.aop.writepages =  kernel.function ("nfs_writepages") !,
+ */
+probe nfs.aop.writepages = kernel.function ("nfs_writepages") !,
              module("nfs").function ("nfs_writepages")
 {
         dev = $mapping->host->i_sb->s_dev
@@ -1044,19 +1051,20 @@ probe nfs.aop.writepages =  kernel.function ("nfs_writepages") !,
         wpages = __nfs_wpages($mapping->host)
 
         name = "nfs.aop.writepages"
-        argstr = sprintf("%d",nr_to_write)
+        argstr = sprintf("%d", nr_to_write)
 
         size = nr_to_write
         units = "pages"         
 }
 
-probe nfs.aop.writepages.return =  kernel.function ("nfs_writepages").return !,
+probe nfs.aop.writepages.return = kernel.function ("nfs_writepages").return !,
              module("nfs").function ("nfs_writepages").return
 {
         name = "nfs.aop.writepages.return"
         retstr = sprintf("%d", $return)
 }
-/*probe nfs.aop.prepare_write
+
+/* probe nfs.aop.prepare_write
  *  Fires when do write operation on nfs.
  *     Prepare a page for writing
  *     Look for a request corresponding to the page. If there
@@ -1072,11 +1080,11 @@ probe nfs.aop.writepages.return =  kernel.function ("nfs_writepages").return !,
  *     offset : start address of this write operation 
  *     to     : end address of this write operation 
  *     page_index : offset within mapping, can used a 
-                     page identifier and position identifier
-                     in the page frame
+ *                   page identifier and position identifier
+ *                   in the page frame
  *     size   : write bytes
-*/
-probe nfs.aop.prepare_write=  kernel.function ("nfs_prepare_write") !,
+ */
+probe nfs.aop.prepare_write = kernel.function ("nfs_prepare_write") !,
              module("nfs").function ("nfs_prepare_write")
 {
         __page = $page
@@ -1104,7 +1112,7 @@ probe nfs.aop.prepare_write.return =
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.aop.commit_write
+/* probe nfs.aop.commit_write
  *  Fires when do a write operation on nfs,
  *  often after prepare_write
  *
@@ -1120,11 +1128,11 @@ probe nfs.aop.prepare_write.return =
  *     i_size : file length in bytes
  *     sb_flag : super block flags
  *     page_index : offset within mapping, can used a 
-                    page identifier and position identifier
-                    in the page frame
+ *                  page identifier and position identifier
+ *                  in the page frame
  *     size   : write bytes
  */ 
-probe nfs.aop.commit_write=  kernel.function ("nfs_commit_write") !,
+probe nfs.aop.commit_write = kernel.function ("nfs_commit_write") !,
              module("nfs").function ("nfs_commit_write")
 {
          __page = $page
@@ -1143,14 +1151,13 @@ probe nfs.aop.commit_write=  kernel.function ("nfs_commit_write") !,
         page_index = $page->index
      
         name = "nfs.aop.commit_write"
-        argstr = sprintf("%d, %d",offset , to)
+        argstr = sprintf("%d, %d", offset, to)
 
         size = to - offset
         units = "bytes"
 }
 
-
-probe nfs.aop.commit_write.return=  
+probe nfs.aop.commit_write.return =
              kernel.function ("nfs_commit_write").return !,
              module("nfs").function ("nfs_commit_write").return
 {
@@ -1158,7 +1165,7 @@ probe nfs.aop.commit_write.return=
         retstr = sprintf("%d", $return)
 }
 
-/*probe nfs.aop.release_page
+/* probe nfs.aop.release_page
  *  Fires when do a release operation on nfs,
  *  
  *
@@ -1167,11 +1174,11 @@ probe nfs.aop.commit_write.return=
  *     dev : device identifier
  *     ino : inode number
  *     page_index : offset within mapping, can used a 
-                    page identifier and position identifier
-                    in the page frame
+ *                  page identifier and position identifier
+ *                  in the page frame
  *     size : release pages
-*/
-probe nfs.aop.release_page =  kernel.function ("nfs_release_page") !,
+ */
+probe nfs.aop.release_page = kernel.function ("nfs_release_page") !,
              module("nfs").function ("nfs_release_page")
 {
         __page = $page
@@ -1189,10 +1196,10 @@ probe nfs.aop.release_page =  kernel.function ("nfs_release_page") !,
 
 }  
 
-probe nfs.aop.release_page.return =  kernel.function ("nfs_release_page").return !,
+probe nfs.aop.release_page.return =
+             kernel.function ("nfs_release_page").return !,
              module("nfs").function ("nfs_release_page").return
 {
         name = "nfs.aop.release_page.return"
         retstr = sprintf("%d", $return)
 }
-
diff --git a/tapsets.cxx b/tapsets.cxx
index 6566c89f..2a893c95 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -228,7 +228,7 @@ common_probe_entryfn_epilogue (translator_output* o,
 
   // Check for excessive skip counts.
   o->newline() << "if (unlikely (atomic_read (& skipped_count) > MAXSKIPPED)) {";
-  o->newline(1) << "if (unlikely (atomic_cmpxchg(& session_state, STAP_SESSION_RUNNING, STAP_SESSION_ERROR) == STAP_SESSION_RUNNING))";
+  o->newline(1) << "if (unlikely (pseudo_atomic_cmpxchg(& session_state, STAP_SESSION_RUNNING, STAP_SESSION_ERROR) == STAP_SESSION_RUNNING))";
   o->newline() << "_stp_error (\"Skipped too many probes, check MAXSKIPPED or try again with stap -t for more details.\");";
   o->newline(-1) << "}";
 
@@ -2911,6 +2911,16 @@ dwarf_derived_probe::saveargs(dwarf_query& q, Dwarf_Die* scope_die, dwarf_var_ex
       dwarf_type_name(&type_die, type_name))
     args.insert("$return:"+type_name);
 
+  /* Pretend that we aren't in a .return for a moment, just so we can
+   * check whether variables are accessible.  We don't want any of the
+   * entry-saving code generated during listing mode.  This works
+   * because the set of $context variables available in a .return
+   * probe (apart from $return) is the same set as available for the
+   * corresponding .call probe, since we collect those variables at
+   * .call time. */
+  bool saved_has_return = has_return;
+  q.has_return = has_return = false;
+
   Dwarf_Die arg;
   vector<Dwarf_Die> scopes = q.dw.getscopes_die(scope_die);
   if (dwarf_child (&scopes[0], &arg) == 0)
@@ -2937,8 +2947,7 @@ dwarf_derived_probe::saveargs(dwarf_query& q, Dwarf_Die* scope_die, dwarf_var_ex
 
         /* trick from visit_target_symbol_context */
         target_symbol *tsym = new target_symbol;
-        token *t = new token;
-        tsym->tok = t;
+        tsym->tok = q.base_loc->tok;
         tsym->base_name = "$";
         tsym->base_name += arg_name;
 
@@ -2949,6 +2958,9 @@ dwarf_derived_probe::saveargs(dwarf_query& q, Dwarf_Die* scope_die, dwarf_var_ex
            args.insert("$"+string(arg_name)+":"+type_name);
       }
     while (dwarf_siblingof (&arg, &arg) == 0);
+
+  /* restore the .return status of the probe */
+  q.has_return = has_return = saved_has_return;
 }
 
 
@@ -4660,7 +4672,7 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline() << "#endif";
   // NB: duplicates common_entryfn_epilogue, but then this is not a probe entry fn epilogue.
   s.op->newline() << "if (unlikely (atomic_inc_return (& skipped_count) > MAXSKIPPED)) {";
-  s.op->newline(1) << "if (unlikely (atomic_cmpxchg(& session_state, STAP_SESSION_RUNNING, STAP_SESSION_ERROR) == STAP_SESSION_RUNNING))";
+  s.op->newline(1) << "if (unlikely (pseudo_atomic_cmpxchg(& session_state, STAP_SESSION_RUNNING, STAP_SESSION_ERROR) == STAP_SESSION_RUNNING))";
   s.op->newline() << "_stp_error (\"Skipped too many probes, check MAXSKIPPED or try again with stap -t for more details.\");";
   s.op->newline(-1) << "}";
   s.op->newline(-1) << "}";
diff --git a/testsuite/buildok/irq.stp b/testsuite/buildok/irq.stp
new file mode 100644
index 00000000..b1a141dc
--- /dev/null
+++ b/testsuite/buildok/irq.stp
@@ -0,0 +1,7 @@
+#! stap -p4
+
+// Tests if all probes in irq tapset are resolvable
+
+probe workqueue.* {}
+probe irq_handler.* {}
+probe softirq.* {}
diff --git a/testsuite/systemtap.examples/interrupt/interrupts-by-dev.stp b/testsuite/systemtap.examples/interrupt/interrupts-by-dev.stp
new file mode 100644
index 00000000..3bcfd5e1
--- /dev/null
+++ b/testsuite/systemtap.examples/interrupt/interrupts-by-dev.stp
@@ -0,0 +1,31 @@
+#! /usr/bin/env stap
+/*
+ *      Copyright (C) 2009 IBM Corp.
+ *      This file is part of systemtap, and is free software.  You can
+ *      redistribute it and/or modify it under the terms of the GNU General
+ *      Public License (GPL); either version 2, or (at your option) any
+ *      later version.
+ *
+ *      Version 1.0     prerna@linux.vnet.ibm.com     2009-10-28
+ *
+ *     Name:
+ *     interrupts-by-dev.stp
+ *
+ *     Description:
+ *     Script to profile interrupts received by each device per 100 ms.
+ *
+ *
+ */
+
+global devices
+
+probe irq_handler.entry {
+        devices[dev_name]++;
+}
+
+probe timer.ms(100) {
+        printf("\t  DEVICE \t NUMBER OF INTERRUPTS \n");
+        foreach ( devname in devices )
+                printf(" %20s :  %5d\n",kernel_string(devname),devices[devname]);
+        delete devices
+}