If SIGUSR2 is sent more than once to cyclictest, truncate the shared
memory file for writing the latest snapshot.
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 2f07426389b3..01ae72f8cdf1 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -234,6 +234,7 @@ static void rstat_setup(void);
static int latency_target_fd = -1;
static int32_t latency_target_value = 0;
+static int rstat_ftruncate(int fd, off_t len);
static int rstat_fd = -1;
/* strlen("/cyclictest") + digits in max pid len + '\0' */
#define SHM_BUF_SIZE 19
@@ -1487,6 +1488,7 @@ static void sighand(int sig)
fprintf(stderr, "ERROR: rstat_fd not valid\n");
return;
}
+ rstat_ftruncate(rstat_fd, 0);
quiet = 0;
dprintf(rstat_fd, "#---------------------------\n");
dprintf(rstat_fd, "# cyclictest current status:\n");
@@ -1835,12 +1837,12 @@ static int rstat_shm_open(void)
return fd;
}
-static int rstat_ftruncate(int fd)
+static int rstat_ftruncate(int fd, off_t len)
{
int err;
errno = 0;
- err = ftruncate(fd, _SC_PAGE_SIZE);
+ err = ftruncate(fd, len);
if (err) {
fprintf(stderr, "ftruncate error %s\n", strerror(errno));
}
@@ -1885,7 +1887,7 @@ static void rstat_setup(void)
if (sfd < 0)
goto rstat_err;
- res = rstat_ftruncate(sfd);
+ res = rstat_ftruncate(sfd, _SC_PAGE_SIZE);
if (res)
goto rstat_err1;
--
2.20.1
