bitkeeper revision 1.911.1.1 (40abd5b2mqoey54uZKqDJrA-dD05Xw)

bandaid for xentrace. Really needs a Xen-visible trace buffer consumer 
index, and a way of kicking the trace deamon...

4 files changed, 14 insertions, 21 deletions

diff --git a/xen/common/dom0_ops.c b/xen/common/dom0_ops.c
index 32fa532c9a..3b413a1faa 100644
--- a/xen/common/dom0_ops.c
+++ b/xen/common/dom0_ops.c
@@ -22,8 +22,8 @@
 #include <hypervisor-ifs/sched_ctl.h>
 
 
-#define TRC_DOM0OP_START_BASE   0x00020000
-#define TRC_DOM0OP_FINISH_BASE  0x00030000
+#define TRC_DOM0OP_ENTER_BASE  0x00020000
+#define TRC_DOM0OP_LEAVE_BASE  0x00030000
 
 
 extern unsigned int alloc_new_dom_mem(struct task_struct *, unsigned int);
@@ -64,7 +64,7 @@ long do_dom0_op(dom0_op_t *u_dom0_op)
         return -EACCES;
     }
 
-    TRACE_5D( TRC_DOM0OP_START_BASE + op->cmd, 
+    TRACE_5D( TRC_DOM0OP_ENTER_BASE + op->cmd, 
 	 0, op->u.dummy[0], op->u.dummy[1], op->u.dummy[2], op->u.dummy[3] );
 
     switch ( op->cmd )
@@ -668,7 +668,7 @@ long do_dom0_op(dom0_op_t *u_dom0_op)
 
     }
 
-    TRACE_5D( TRC_DOM0OP_FINISH_BASE + op->cmd, ret,
+    TRACE_5D( TRC_DOM0OP_LEAVE_BASE + op->cmd, ret,
 	 op->u.dummy[0], op->u.dummy[1], op->u.dummy[2], op->u.dummy[3]  );
 
 
diff --git a/xen/common/trace.c b/xen/common/trace.c
index 0140e7444a..e79c97ee54 100644
--- a/xen/common/trace.c
+++ b/xen/common/trace.c
@@ -27,7 +27,6 @@
 #include <xen/sched.h>
 #include <xen/slab.h>
 #include <xen/smp.h>
-#include <xen/spinlock.h>
 #include <xen/trace.h>
 #include <xen/errno.h>
 #include <asm/atomic.h>
@@ -86,7 +85,6 @@ void init_trace_bufs(void)
         /* For use in Xen. */
         buf->vdata    = (struct t_rec *)(buf+1);
         buf->head_ptr = buf->vdata;
-        spin_lock_init(&buf->lock);
         
         /* For use in user space. */
         buf->data = (struct t_rec *)__pa(buf->vdata);
diff --git a/xen/include/hypervisor-ifs/trace.h b/xen/include/hypervisor-ifs/trace.h
index 4d267ba101..d201eceb88 100644
--- a/xen/include/hypervisor-ifs/trace.h
+++ b/xen/include/hypervisor-ifs/trace.h
@@ -20,13 +20,12 @@ struct t_buf {
     struct t_rec *data;     /* pointer to data area.  physical address
                              * for convenience in user space code            */
 
-    unsigned int size;      /* size of the data area, in t_recs              */
-    unsigned int head;      /* array index of the most recent record         */
+    unsigned long size;      /* size of the data area, in t_recs              */
+    unsigned long head;      /* array index of the most recent record         */
 
 #ifdef __KERNEL__
     struct t_rec *head_ptr; /* pointer to the head record                    */
     struct t_rec *vdata;    /* virtual address pointer to data               */
-    spinlock_t lock;        /* ensure mutually exlusive access (for inserts) */
 #endif
 
     /* never add anything here - the kernel stuff must be the last elements */
diff --git a/xen/include/xen/trace.h b/xen/include/xen/trace.h
index 00b18b0211..782023f76e 100644
--- a/xen/include/xen/trace.h
+++ b/xen/include/xen/trace.h
@@ -61,10 +61,12 @@ static inline int trace(u32 event, u32 d1, u32 d2, u32 d3, u32 d4, u32 d5)
     if ( !tb_init_done )
         return -1;
 
+
     buf = t_bufs[smp_processor_id()];
-    rec = buf->head_ptr;
 
-    spin_lock_irqsave(&buf->lock, flags);
+    local_irq_save(flags);
+
+    rec = buf->head_ptr;
 
     rdtscll(rec->cycles);
     rec->event = event;
@@ -76,18 +78,12 @@ static inline int trace(u32 event, u32 d1, u32 d2, u32 d3, u32 d4, u32 d5)
 
     wmb(); /* above must be visible before reader sees index updated */
 
-    if ( likely(buf->head_ptr < (buf->vdata + buf->size - 1)) )
-    {
-        buf->head_ptr++;
-        buf->head++;
-    }
-    else
-    {
-        buf->head = 0;
+    buf->head_ptr++;
+    buf->head++;
+    if ( buf->head_ptr == (buf->vdata + (buf->size-1)) )
         buf->head_ptr = buf->vdata;
-    }
 
-    spin_unlock_irqrestore(&buf->lock, flags);
+    local_irq_restore(flags);
     
     return 0;
 }