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Message-Id: <20231024092634.7122-11-ilpo.jarvinen@linux.intel.com>
Date: Tue, 24 Oct 2023 12:26:20 +0300
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: linux-kselftest@...r.kernel.org,
Reinette Chatre <reinette.chatre@...el.com>,
Shuah Khan <shuah@...nel.org>,
Shaopeng Tan <tan.shaopeng@...fujitsu.com>,
Maciej Wieczór-Retman
<maciej.wieczor-retman@...el.com>,
Fenghua Yu <fenghua.yu@...el.com>
Cc: linux-kernel@...r.kernel.org,
Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Subject: [PATCH 10/24] selftests/resctrl: Remove nested calls in perf event handling
Perf event handling has functions that are the sole caller of another
perf event handling related function:
- reset_enable_llc_perf() calls perf_event_open_llc_miss()
- reset_enable_llc_perf() calls ioctl_perf_event_ioc_reset_enable()
- measure_llc_perf() calls get_llc_perf()
Remove the extra layer of calls to make the code easier to follow by
moving the code into the calling function.
In addition, converts print_results_cache() unsigned long parameter to
__u64 that matches the type coming from perf.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
---
tools/testing/selftests/resctrl/cache.c | 86 +++++++------------------
1 file changed, 25 insertions(+), 61 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index d39ef4eebc37..208af1ecae28 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -29,25 +29,6 @@ static void initialize_perf_event_attr(void)
pea_llc_miss.disabled = 1;
}
-static void ioctl_perf_event_ioc_reset_enable(void)
-{
- ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
- ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
-}
-
-static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
-{
- fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1,
- PERF_FLAG_FD_CLOEXEC);
- if (fd_lm == -1) {
- perror("Error opening leader");
- ctrlc_handler(0, NULL, NULL);
- return -1;
- }
-
- return 0;
-}
-
static void initialize_llc_perf(void)
{
memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr));
@@ -63,42 +44,16 @@ static void initialize_llc_perf(void)
static int reset_enable_llc_perf(pid_t pid, int cpu_no)
{
- int ret = 0;
-
- ret = perf_event_open_llc_miss(pid, cpu_no);
- if (ret < 0)
- return ret;
-
- /* Start counters to log values */
- ioctl_perf_event_ioc_reset_enable();
-
- return 0;
-}
-
-/*
- * get_llc_perf: llc cache miss through perf events
- * @llc_perf_miss: LLC miss counter that is filled on success
- *
- * Perf events like HW_CACHE_MISSES could be used to validate number of
- * cache lines allocated.
- *
- * Return: =0 on success. <0 on failure.
- */
-static int get_llc_perf(__u64 *llc_perf_miss)
-{
- int ret;
-
- /* Stop counters after one span to get miss rate */
-
- ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
-
- ret = read(fd_lm, &rf_cqm, sizeof(struct read_format));
- if (ret == -1) {
- perror("Could not get llc misses through perf");
+ fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC);
+ if (fd_lm == -1) {
+ perror("Error opening leader");
+ ctrlc_handler(0, NULL, NULL);
return -1;
}
- *llc_perf_miss = rf_cqm.values[0].value;
+ /* Start counters to log values */
+ ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
+ ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
return 0;
}
@@ -166,20 +121,29 @@ static int print_results_cache(char *filename, int bm_pid, __u64 llc_value)
return 0;
}
+/*
+ * measure_llc_perf: measure perf events
+ * @bm_pid: child pid that runs benchmark
+ *
+ * Measure things like cache misses from perf events.
+ *
+ * Return: =0 on success. <0 on failure.
+ */
static int measure_llc_perf(struct resctrl_val_param *param, int bm_pid)
{
- __u64 llc_perf_miss = 0;
int ret;
- /*
- * Measure cache miss from perf.
- */
- ret = get_llc_perf(&llc_perf_miss);
- if (ret < 0)
- return ret;
+ /* Stop counters after one span to get miss rate */
+ ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
- ret = print_results_cache(param->filename, bm_pid, llc_perf_miss);
- return ret;
+ ret = read(fd_lm, &rf_cqm, sizeof(struct read_format));
+ close(fd_lm);
+ if (ret == -1) {
+ perror("Could not get perf value");
+ return -1;
+ }
+
+ return print_results_cache(param->filename, bm_pid, rf_cqm.values[0].value);
}
int measure_llc_resctrl(struct resctrl_val_param *param, int bm_pid)
--
2.30.2
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