From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael J. Ruhl" Subject: [PATCH rdma-core v4 4/4] ibacm: Use MONOTONIC time base to avoid timer expiration issues Date: Wed, 15 Nov 2017 14:35:35 -0500 Message-ID: <20171115193524.470.17499.stgit@phlsvslse11.ph.intel.com> References: <20171115193155.470.85049.stgit@phlsvslse11.ph.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171115193155.470.85049.stgit-K+u1se/DcYrLESAwzcoQNrvm/XP+8Wra@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org From: Michael J. Ruhl The event_wait() function uses the CLOCK_REALTIME time base for calculating expiration times (default time base for gettimeofday()). Using the CLOCK_REALTIME time base can introduce incorrect expiration timeout calculations if the REALTIME clock changes, making a timeout too long (possibly hours or days), or too short. Update time base usage to the CLOCK_MONOTONIC time base to avoid time change issues. Use appropriate typing to avoid unnecessary typecasting. Reviewed-by: Mike Marciniszyn Signed-off-by: Michael J. Ruhl --- ibacm/linux/osd.h | 22 ++++++++++++---------- 1 files changed, 12 insertions(+), 10 deletions(-) diff --git a/ibacm/linux/osd.h b/ibacm/linux/osd.h index eabf5ed..4ef7b55 100644 --- a/ibacm/linux/osd.h +++ b/ibacm/linux/osd.h @@ -88,20 +88,23 @@ typedef struct { volatile int val; } atomic_t; typedef struct { pthread_cond_t cond; pthread_mutex_t mutex; } event_t; static inline void event_init(event_t *e) { - pthread_cond_init(&e->cond, NULL); + pthread_condattr_t attr; + + pthread_condattr_init(&attr); + pthread_condattr_setclock(&attr, CLOCK_MONOTONIC); + pthread_cond_init(&e->cond, &attr); pthread_mutex_init(&e->mutex, NULL); } #define event_signal(e) pthread_cond_signal(&(e)->cond) #define ONE_SEC_IN_NSEC 1000000000ULL -static inline int event_wait(event_t *e, int timeout) +static inline int event_wait(event_t *e, unsigned int timeout) { - struct timeval curtime; struct timespec wait; int ret; - gettimeofday(&curtime, NULL); - wait.tv_sec = curtime.tv_sec + ((unsigned) timeout) / 1000; - wait.tv_nsec = (curtime.tv_usec + (((unsigned) timeout) % 1000) * 1000) * 1000; + clock_gettime(CLOCK_MONOTONIC, &wait); + wait.tv_sec = wait.tv_sec + timeout / 1000; + wait.tv_nsec = wait.tv_nsec + (timeout % 1000) * 1000000; if (wait.tv_nsec > ONE_SEC_IN_NSEC) { wait.tv_sec++; wait.tv_nsec -= ONE_SEC_IN_NSEC; @@ -114,10 +117,9 @@ static inline int event_wait(event_t *e, int timeout) static inline uint64_t time_stamp_us(void) { - struct timeval curtime; - timerclear(&curtime); - gettimeofday(&curtime, NULL); - return (uint64_t) curtime.tv_sec * 1000000 + (uint64_t) curtime.tv_usec; + struct timespec t; + clock_gettime(CLOCK_MONOTONIC, &t); + return (t.tv_sec * ONE_SEC_IN_NSEC + t.tv_nsec) / 1000; } #define time_stamp_ms() (time_stamp_us() / (uint64_t) 1000) -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html