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test: perf: prevent overflow counter from stopping counter

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Fixes: 1a204b6 "perf: overflow test"
Change-Id: I4d8e93b97f7a8d58ef7811f55b5c995b16c5af69
This commit is contained in:
Masamichi Takagi
2020-03-27 02:12:04 -04:00
parent d086100b35
commit c3c0b7197f
3 changed files with 32 additions and 2 deletions
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26
test/perf_overflow/combination_test.c
View File

@ -1,5 +1,6 @@
/* combination_test.c COPYRIGHT FUJITSU LIMITED 2019 */
#include "combination_test.h"
#include "perf_common.h"
//
// main
@ -32,6 +33,31 @@ static int combination_test(struct command_set *cmd_set)
goto out;
}
/* Set reasonable value to overflow counter so as not to stop
* counter on Linux. Reset must precede to prevent
* uninitialized value is accumulated on McKernel for the case
* REFRESH includes ENABLE
*/
ret = perf_event_ioc_refresh(fd, NULL);
if (ret < 0) {
perror("perf_event_ioc_refresh");
goto out;
}
/* Stop counter for the case REFRESH includes ENABLE */
ret = asm_ioctl3(fd, PERF_EVENT_IOC_DISABLE, 0);
if (ret < 0) {
errno = -ret;
perror("asm_ioctl(PERF_EVENT_IOC_DISABLE)");
goto out;
}
ret = ioctl(fd, PERF_EVENT_IOC_RESET, 0);
if (ret < 0) {
perror("ioctl(PERF_EVENT_IOC_RESET)");
goto out;
}
ret = asm_ioctl3(fd, PERF_EVENT_IOC_ENABLE, 0);
if (ret < 0) {
errno = -ret;

7
test/perf_overflow/perf_common.c
View File

@ -164,9 +164,12 @@ static void build_perf_event_ioc_reset(struct command *cmd)
}
// perf_event_ioc_refresh command
static int perf_event_ioc_refresh(int fd, void *_args)
int perf_event_ioc_refresh(int fd, void *_args)
{
int ret = asm_ioctl3(fd, PERF_EVENT_IOC_REFRESH, 0);
/* Prevent overflow counter from stopping counter
* Note that it starts counter as well
*/
int ret = asm_ioctl3(fd, PERF_EVENT_IOC_REFRESH, 256);
if (ret < 0) {
errno = -ret;

1
test/perf_overflow/perf_common.h
View File

@ -25,6 +25,7 @@ void print_usage(void);
//system call
long perf_event_open(struct perf_event_attr *event_attr, pid_t pid,
int cpu, int group_fd, unsigned long flags);
int perf_event_ioc_refresh(int fd, void *_args);
int init_perf_event_attr(struct perf_event_attr *event_attr);
int asm_ioctl3(int fd, unsigned long arg1, unsigned long arg2);
int asm_read(int fd, void *buf, size_t size);