lockmeter: fix lock counter roll over issue

Xuekun Hu
2005-08-14T04:01:04Z

When I collected lockmeter data for a longer duration, sometimes the
locks counter could roll over. I'm sure someone else maybe meet the
same situation. So I wrote the below patch, could you have a look?

diff -Nraup linux/include/linux/lockmeter.h
linux.lockmeter/include/linux/lockmeter.h
--- linux/include/linux/lockmeter.h 2005-08-09 10:46:53.302083832 +0800
+++ linux.lockmeter/include/linux/lockmeter.h 2005-08-05
17:22:37.000000000 +0800
@@ -150,7 +150,7 @@ typedef struct {
uint32_t max_wait_ww_ticks; /* max wait time writer vs writer */
/* prev 2 only used for write locks*/
uint32_t acquire_time; /* time lock acquired this CPU */
- uint32_t count[LSTAT_ACT_MAX_VALUES];
+ uint64_t count[LSTAT_ACT_MAX_VALUES];
} lstat_lock_counts_t;

typedef lstat_lock_counts_t lstat_cpu_counts_t[LSTAT_MAX_STAT_INDEX];
@@ -167,7 +167,7 @@ typedef lstat_lock_counts_t lstat_cpu_co
#define LSTAT_MAX_READ_LOCK_INDEX 1000
typedef struct {
POINTER lock_ptr; /* address of lock for output stats */
- uint32_t read_lock_count;
+ uint64_t read_lock_count;
int64_t cum_hold_ticks; /* sum of read lock hold times over */
/* all callers. ....................*/
uint32_t write_index; /* last write lock hash table index */

I also modified lockstat to compliant with this modification against
lockstat 1.4.11 version.

diff -Nraup lockstat/include/linux/lockmeter.h
lockstat.fix/include/linux/lockmeter.h
--- lockstat/include/linux/lockmeter.h 2004-09-14 07:02:05.000000000 +0800
+++ lockstat.fix/include/linux/lockmeter.h 2005-08-05 17:38:46.000000000 +0800
@@ -150,7 +150,7 @@ typedef struct {
uint32_t max_wait_ww_ticks; /* max wait time writer vs writer */
/* prev 2 only used for write locks*/
uint32_t acquire_time; /* time lock acquired this CPU */
- uint32_t count[LSTAT_ACT_MAX_VALUES];
+ uint64_t count[LSTAT_ACT_MAX_VALUES];
} lstat_lock_counts_t;

typedef lstat_lock_counts_t lstat_cpu_counts_t[LSTAT_MAX_STAT_INDEX];
@@ -167,7 +167,7 @@ typedef lstat_lock_counts_t lstat_cpu_co
#define LSTAT_MAX_READ_LOCK_INDEX 1000
typedef struct {
POINTER lock_ptr; /* address of lock for output stats */
- uint32_t read_lock_count;
+ uint64_t read_lock_count;
int64_t cum_hold_ticks; /* sum of read lock hold times over */
/* all callers. ....................*/
uint32_t write_index; /* last write lock hash table index */
diff -Nraup lockstat/lockstat.c lockstat.fix/lockstat.c
--- lockstat/lockstat.c 2004-09-14 07:01:41.000000000 +0800
+++ lockstat.fix/lockstat.c 2005-08-09 10:35:18.305356776 +0800
@@ -36,7 +36,7 @@ static char lockstat_version[] = "1.4.1
#include <stdlib.h>
#include <string.h>
#include <errno.h>
-#include <sys/time.h>
+#include <time.h>
#include <linux/lockmeter.h>

extern void closeFiles(void);
@@ -267,7 +267,7 @@ typedef enum {Null_Entry, Spin_Entry, RL

typedef struct {
lstat_lock_counts_t counts;
- uint32_t total;
+ uint64_t total;
double contention;
double persec;
double utilization;
@@ -999,7 +999,8 @@ add_counts(lock_summary_t *sump, lstat_l
int
sum_counts(lock_summary_t *sump, entry_type_enum entry_type)
{
- int total, i, j;
+ int i, j;
+ uint64_t total;
double contention;
double utilization;

@@ -1171,7 +1172,7 @@ print_lock(char *name, lock_summary_t *s
float mean_hold_time, max_hold_time;
float wait_time, mean_wait_time, max_wait_time, mean_wait_ww_time,
max_wait_ww_time;
double temp_time;
- uint32_t total_spin_count = 0;
+ uint64_t total_spin_count = 0;

print_header();

@@ -1317,7 +1318,7 @@ print_lock(char *name, lock_summary_t *s
}

/* following done for ALL types of locks, except as indicated */
- printf(" %9d", sump->total);
+ printf(" %20ld", sump->total);
print_percentage('
',100.0*(double)sump->counts.count[LSTAT_ACT_NO_WAIT]/(double)sump->total,0);
print_percentage('
',100.0*(double)sump->counts.count[LSTAT_ACT_SPIN]/(double)sump->total,0);
if (entry_type == WLspin_Entry) {
@@ -1325,7 +1326,7 @@ print_lock(char *name, lock_summary_t *s
')');
}
#ifdef notyet
- printf("%9d", sump->counts.count[LSTAT_ACT_SLEPT]);
+ printf("%20ld", sump->counts.count[LSTAT_ACT_SLEPT]);
#endif
if (entry_type == Spin_Entry) {
/* We only see these for spinlock_t, and even then it's rare. */

Any comments?