This is a note to let you know that I've just added the patch titled sfc: PTP: Moderate log message on event queue overflow to the 3.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sfc-ptp-moderate-log-message-on-event-queue-overflow.patch and it can be found in the queue-3.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Jan 13 09:44:41 PST 2014 From: Laurence Evans <levans@xxxxxxxxxxxxxx> Date: Mon, 28 Jan 2013 14:51:17 +0000 Subject: sfc: PTP: Moderate log message on event queue overflow From: Laurence Evans <levans@xxxxxxxxxxxxxx> [ Upstream commit f32116003c39f3a6815215a7512e1ea8d1e4bbc7 ] Limit syslog flood if a PTP packet storm occurs. Fixes: 7c236c43b838 ('sfc: Add support for IEEE-1588 PTP') Signed-off-by: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/sfc/ptp.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/sfc/ptp.c +++ b/drivers/net/ethernet/sfc/ptp.c @@ -220,6 +220,7 @@ struct efx_ptp_timeset { * @evt_list: List of MC receive events awaiting packets * @evt_free_list: List of free events * @evt_lock: Lock for manipulating evt_list and evt_free_list + * @evt_overflow: Boolean indicating that event list has overflowed * @rx_evts: Instantiated events (on evt_list and evt_free_list) * @workwq: Work queue for processing pending PTP operations * @work: Work task @@ -270,6 +271,7 @@ struct efx_ptp_data { struct list_head evt_list; struct list_head evt_free_list; spinlock_t evt_lock; + bool evt_overflow; struct efx_ptp_event_rx rx_evts[MAX_RECEIVE_EVENTS]; struct workqueue_struct *workwq; struct work_struct work; @@ -635,6 +637,11 @@ static void efx_ptp_drop_time_expired_ev } } } + /* If the event overflow flag is set and the event list is now empty + * clear the flag to re-enable the overflow warning message. + */ + if (ptp->evt_overflow && list_empty(&ptp->evt_list)) + ptp->evt_overflow = false; spin_unlock_bh(&ptp->evt_lock); } @@ -676,6 +683,11 @@ static enum ptp_packet_state efx_ptp_mat break; } } + /* If the event overflow flag is set and the event list is now empty + * clear the flag to re-enable the overflow warning message. + */ + if (ptp->evt_overflow && list_empty(&ptp->evt_list)) + ptp->evt_overflow = false; spin_unlock_bh(&ptp->evt_lock); return rc; @@ -809,6 +821,7 @@ static int efx_ptp_stop(struct efx_nic * list_for_each_safe(cursor, next, &efx->ptp_data->evt_list) { list_move(cursor, &efx->ptp_data->evt_free_list); } + ptp->evt_overflow = false; spin_unlock_bh(&efx->ptp_data->evt_lock); return rc; @@ -901,6 +914,7 @@ static int efx_ptp_probe_channel(struct spin_lock_init(&ptp->evt_lock); for (pos = 0; pos < MAX_RECEIVE_EVENTS; pos++) list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list); + ptp->evt_overflow = false; ptp->phc_clock_info.owner = THIS_MODULE; snprintf(ptp->phc_clock_info.name, @@ -1299,8 +1313,13 @@ static void ptp_event_rx(struct efx_nic list_add_tail(&evt->link, &ptp->evt_list); queue_work(ptp->workwq, &ptp->work); - } else { - netif_err(efx, rx_err, efx->net_dev, "No free PTP event"); + } else if (!ptp->evt_overflow) { + /* Log a warning message and set the event overflow flag. + * The message won't be logged again until the event queue + * becomes empty. + */ + netif_err(efx, rx_err, efx->net_dev, "PTP event queue overflow\n"); + ptp->evt_overflow = true; } spin_unlock_bh(&ptp->evt_lock); } Patches currently in stable-queue which might be from levans@xxxxxxxxxxxxxx are queue-3.12/sfc-ptp-moderate-log-message-on-event-queue-overflow.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html