Re: lockmeter: fix lock counter roll over issue

Xuekun Hu
2005-08-15T07:35:55Z

Does anyone have inputs?

On 8/14/05, Xuekun Hu <xuekun.hu@gmail.com> wrote:
> 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?
>