Hi, Morten,
fixed in v2, thanks.
在 2021/4/28 18:59, Morten Brørup 写道:
From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of fengchengwen
Sent: Wednesday, April 28, 2021 12:36 PM
On 2021/4/28 17:24, Morten Brørup wrote:
From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Min Hu (Connor)
Sent: Wednesday, April 28, 2021 10:13 AM
From: Chengwen Feng <fengcheng...@huawei.com>
Currently, the mp uses gettimeofday() API to get the time, and used
as
timeout parameter.
But the time which gets from gettimeofday() API isn't monotonically
increasing. The process may fail if the system time is changed.
This fixes it by using clock_gettime() API with monotonic
attribution.
Fixes: 783b6e54971d ("eal: add synchronous multi-process
communication")
Fixes: f05e26051c15 ("eal: add IPC asynchronous request")
Cc: sta...@dpdk.org
Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
Signed-off-by: Min Hu (Connor) <humi...@huawei.com>
---
lib/eal/common/eal_common_proc.c | 45 +++++++++++++++++------------
---
--------
1 file changed, 19 insertions(+), 26 deletions(-)
diff --git a/lib/eal/common/eal_common_proc.c
b/lib/eal/common/eal_common_proc.c
index 6d1af3c..7f08826 100644
--- a/lib/eal/common/eal_common_proc.c
+++ b/lib/eal/common/eal_common_proc.c
@@ -40,6 +40,12 @@ static char mp_dir_path[PATH_MAX]; /* The
directory
path for all mp sockets */
static pthread_mutex_t mp_mutex_action = PTHREAD_MUTEX_INITIALIZER;
static char peer_name[PATH_MAX];
+#ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
+#else
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC
+#endif
Just out of curiosity: Why do you prefer CLOCK_MONOTONIC_RAW over
CLOCK_MONOTONIC?
there may slightly difference, the CLOCK_MONOTONIC_RAW is totally local
oscillator
(pls see below link), just preferred in engineering practice.
https://stackoverflow.com/questions/14270300/what-is-the-difference-
between-clock-monotonic-clock-monotonic-raw
Interesting link! Following the treads there, it looks like CLOCK_MONOTONIC had
a bug in some old kernel versions, where in certain circumstances it could jump
slightly backwards.
That bug seems to have been fixed, so CLOCK_MONOTONIC should be safe to use.
Source: https://bugzilla.redhat.com/show_bug.cgi?id=448449
+
struct action_entry {
TAILQ_ENTRY(action_entry) next;
char action_name[RTE_MP_MAX_NAME_LEN];
@@ -490,14 +496,8 @@ async_reply_handle_thread_unsafe(void *arg)
struct pending_request *req = (struct pending_request *)arg;
enum async_action action;
struct timespec ts_now;
- struct timeval now;
- if (gettimeofday(&now, NULL) < 0) {
- RTE_LOG(ERR, EAL, "Cannot get current time\n");
- goto no_trigger;
- }
- ts_now.tv_nsec = now.tv_usec * 1000;
- ts_now.tv_sec = now.tv_sec;
+ clock_gettime(CLOCK_TYPE_ID, &ts_now);
action = process_async_request(req, &ts_now);
@@ -896,6 +896,7 @@ mp_request_sync(const char *dst, struct
rte_mp_msg
*req,
struct rte_mp_reply *reply, const struct timespec *ts)
{
int ret;
+ pthread_condattr_t attr;
struct rte_mp_msg msg, *tmp;
struct pending_request pending_req, *exist;
@@ -904,7 +905,9 @@ mp_request_sync(const char *dst, struct
rte_mp_msg
*req,
strlcpy(pending_req.dst, dst, sizeof(pending_req.dst));
pending_req.request = req;
pending_req.reply = &msg;
- pthread_cond_init(&pending_req.sync.cond, NULL);
+ pthread_condattr_init(&attr);
+ pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
Shouldn't CLOCK_MONOTONIC be CLOCK_TYPE_ID here too?
After reading the source code, it only support CLOCK_MONOTONIC and
CLOCK_REALTIME
(pls see below link), so cant't use CLOCK_TYPE_ID here.
https://code.woboq.org/userspace/glibc/nptl/pthread_condattr_setclock.c
.html#pthread_condattr_setclock
will fix in v2 by make CLOCK_TYPE_ID equal CLOCK_MONOTONIC.
OK, then just get rid of the CLOCK_TYPE_ID definition and use CLOCK_MONOTONIC
instead.
thanks
+ pthread_cond_init(&pending_req.sync.cond, &attr);
exist = find_pending_request(dst, req->name);
if (exist) {
@@ -967,8 +970,7 @@ rte_mp_request_sync(struct rte_mp_msg *req,
struct
rte_mp_reply *reply,
int dir_fd, ret = -1;
DIR *mp_dir;
struct dirent *ent;
- struct timeval now;
- struct timespec end;
+ struct timespec now, end;
const struct internal_config *internal_conf =
eal_get_internal_configuration();
@@ -987,15 +989,10 @@ rte_mp_request_sync(struct rte_mp_msg *req,
struct rte_mp_reply *reply,
return -1;
}
- if (gettimeofday(&now, NULL) < 0) {
- RTE_LOG(ERR, EAL, "Failed to get current time\n");
- rte_errno = errno;
- goto end;
- }
-
- end.tv_nsec = (now.tv_usec * 1000 + ts->tv_nsec) % 1000000000;
+ clock_gettime(CLOCK_TYPE_ID, &now);
+ end.tv_nsec = (now.tv_nsec + ts->tv_nsec) % 1000000000;
end.tv_sec = now.tv_sec + ts->tv_sec +
- (now.tv_usec * 1000 + ts->tv_nsec) / 1000000000;
+ (now.tv_nsec + ts->tv_nsec) / 1000000000;
/* for secondary process, send request to the primary process
only */
if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
@@ -1069,7 +1066,7 @@ rte_mp_request_async(struct rte_mp_msg *req,
const struct timespec *ts,
int dir_fd, ret = 0;
DIR *mp_dir;
struct dirent *ent;
- struct timeval now;
+ struct timespec now;
struct timespec *end;
bool dummy_used = false;
const struct internal_config *internal_conf =
@@ -1086,11 +1083,6 @@ rte_mp_request_async(struct rte_mp_msg *req,
const struct timespec *ts,
return -1;
}
- if (gettimeofday(&now, NULL) < 0) {
- RTE_LOG(ERR, EAL, "Failed to get current time\n");
- rte_errno = errno;
- return -1;
- }
copy = calloc(1, sizeof(*copy));
dummy = calloc(1, sizeof(*dummy));
param = calloc(1, sizeof(*param));
@@ -1108,9 +1100,10 @@ rte_mp_request_async(struct rte_mp_msg *req,
const struct timespec *ts,
end = ¶m->end;
reply = ¶m->user_reply;
- end->tv_nsec = (now.tv_usec * 1000 + ts->tv_nsec) % 1000000000;
+ clock_gettime(CLOCK_TYPE_ID, &now);
+ end->tv_nsec = (now.tv_nsec + ts->tv_nsec) % 1000000000;
end->tv_sec = now.tv_sec + ts->tv_sec +
- (now.tv_usec * 1000 + ts->tv_nsec) / 1000000000;
+ (now.tv_nsec + ts->tv_nsec) / 1000000000;
reply->nb_sent = 0;
reply->nb_received = 0;
reply->msgs = NULL;
--
2.7.4
