Hmm... this has the unfortunate side-effect of doubling the size of
the trace, and effectively halving the effectiveness of the trace
buffer in avoiding drops. My moderate-length traces are already in
the gigabyte range, and I occasionally lose trace records even with a
buffer size of 256. It would be really nice if we could avoid that.
I happen to be using the VMENTER/VMEXIT tracing, which could be
consolidated into one record if we went to a 64-bit trace. Is anyone
else doing high-bandwidth tracing that this would affect in a
significantly negative way?
-George
On 11/30/06, Tony Breeds <tony@xxxxxxxxxxxxxxxxxx> wrote:
Signed-off-by: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>
---
xen/common/trace.c | 6 +++---
xen/include/public/trace.h | 2 +-
xen/include/xen/trace.h | 14 +++++++-------
3 files changed, 11 insertions(+), 11 deletions(-)
Index: xen-unstable.hg-mainline.xentrace/xen/common/trace.c
===================================================================
--- xen-unstable.hg-mainline.xentrace.orig/xen/common/trace.c
+++ xen-unstable.hg-mainline.xentrace/xen/common/trace.c
@@ -46,7 +46,7 @@ static int nr_recs;
static int t_buf_highwater;
/* Number of records lost due to per-CPU trace buffer being full. */
-static DEFINE_PER_CPU(unsigned long, lost_records);
+static DEFINE_PER_CPU(uint64_t, lost_records);
/* a flag recording whether initialization has been done */
/* or more properly, if the tbuf subsystem is enabled right now */
@@ -228,8 +228,8 @@ int tb_control(xen_sysctl_tbuf_op_t *tbc
* failure, otherwise 0. Failure occurs only if the trace buffers are not yet
* initialised.
*/
-void trace(u32 event, unsigned long d1, unsigned long d2,
- unsigned long d3, unsigned long d4, unsigned long d5)
+void trace(uint32_t event, uint64_t d1, uint64_t d2, uint64_t d3, uint64_t d4,
+ uint64_t d5)
{
struct t_buf *buf;
struct t_rec *rec;
Index: xen-unstable.hg-mainline.xentrace/xen/include/public/trace.h
===================================================================
--- xen-unstable.hg-mainline.xentrace.orig/xen/include/public/trace.h
+++ xen-unstable.hg-mainline.xentrace/xen/include/public/trace.h
@@ -76,7 +76,7 @@
struct t_rec {
uint64_t cycles; /* cycle counter timestamp */
uint32_t event; /* event ID */
- unsigned long data[5]; /* event data items */
+ uint64_t data[5]; /* event data items */
};
/*
Index: xen-unstable.hg-mainline.xentrace/xen/include/xen/trace.h
===================================================================
--- xen-unstable.hg-mainline.xentrace.orig/xen/include/xen/trace.h
+++ xen-unstable.hg-mainline.xentrace/xen/include/xen/trace.h
@@ -33,19 +33,19 @@ void init_trace_bufs(void);
/* used to retrieve the physical address of the trace buffers */
int tb_control(struct xen_sysctl_tbuf_op *tbc);
-void trace(u32 event, unsigned long d1, unsigned long d2,
- unsigned long d3, unsigned long d4, unsigned long d5);
+void trace(uint32_t event, uint64_t d1, uint64_t d2, uint64_t d3, uint64_t d4,
+ uint64_t d5);
/* Avoids troubling the caller with casting their arguments to a trace macro */
#define trace_do_casts(e,d1,d2,d3,d4,d5) \
do { \
if ( unlikely(tb_init_done) ) \
trace(e, \
- (unsigned long)d1, \
- (unsigned long)d2, \
- (unsigned long)d3, \
- (unsigned long)d4, \
- (unsigned long)d5); \
+ (uint64_t)d1, \
+ (uint64_t)d2, \
+ (uint64_t)d3, \
+ (uint64_t)d4, \
+ (uint64_t)d5); \
} while ( 0 )
/* Convenience macros for calling the trace function. */
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home