When running multiple instances of cyclictest, getting a snapshot from
one will overwrite any snapshots from other instances.
So, create a different shm_file based on the pid for each instance.
For example if you have two instances of cyclictest running
ls /dev/shm/
cyclictest8264 cyclictest8276
You can also use the pid from the file name to know where to send
SIGUSR2
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index beac9a3ce946..2f07426389b3 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -235,6 +235,9 @@ static int latency_target_fd = -1;
static int32_t latency_target_value = 0;
static int rstat_fd = -1;
+/* strlen("/cyclictest") + digits in max pid len + '\0' */
+#define SHM_BUF_SIZE 19
+static char shm_name[SHM_BUF_SIZE];
/* Latency trick
* if the file /dev/cpu_dma_latency exists,
@@ -1806,9 +1809,15 @@ static void trigger_update(struct thread_param *par, int diff, int64_t ts)
static int rstat_shm_open(void)
{
int fd;
+ pid_t pid;
+
+ pid = getpid();
+ printf("pid = %d", pid);
+
+ snprintf(shm_name, SHM_BUF_SIZE, "%s%d", "/cyclictest", pid);
errno = 0;
- fd = shm_unlink("/cyclictest_shm");
+ fd = shm_unlink(shm_name);
if ((fd == -1) && (errno != ENOENT)) {
fprintf(stderr, "ERROR: shm_unlink %s\n", strerror(errno));
@@ -1816,7 +1825,7 @@ static int rstat_shm_open(void)
}
errno = 9;
- fd = shm_open("/cyclictest_shm", O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+ fd = shm_open(shm_name, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
if (fd == -1) {
fprintf(stderr, "ERROR: shm_open %s\n", strerror(errno));
}
@@ -1894,7 +1903,7 @@ rstat_err2:
munmap(mptr, _SC_PAGE_SIZE);
rstat_err1:
close(sfd);
- shm_unlink("/cyclictest_shm");
+ shm_unlink(shm_name);
rstat_err:
rstat_fd = -1;
return;
@@ -2317,7 +2326,7 @@ int main(int argc, char **argv)
/* Remove running status shared memory file if it exists */
if (rstat_fd >= 0)
- shm_unlink("/cyclictest_shm");
+ shm_unlink(shm_name);
exit(ret);
}
--
2.20.1
