From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47744 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726884AbgKQQPh (ORCPT ); Tue, 17 Nov 2020 11:15:37 -0500 From: Julian Wiedmann Subject: [PATCH net-next 2/9] s390/qeth: reduce rtnl locking for switchdev events Date: Tue, 17 Nov 2020 17:15:13 +0100 Message-Id: <20201117161520.1089-3-jwi@linux.ibm.com> In-Reply-To: <20201117161520.1089-1-jwi@linux.ibm.com> References: <20201117161520.1089-1-jwi@linux.ibm.com> List-ID: To: David Miller , Jakub Kicinski Cc: linux-netdev , linux-s390 , Heiko Carstens , Karsten Graul , Julian Wiedmann call_switchdev_notifiers() doesn't require holding the RTNL lock since commit ff5cf100110c ("net: switchdev: Change notifier chain to be atomic"). We still need it for the "lost event" slow path, to avoid racing against a concurrent .ndo_bridge_setlink(). Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter --- drivers/s390/net/qeth_l2_main.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 28f6dda95736..daeb837abec3 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -737,8 +737,6 @@ static void qeth_l2_dev2br_an_set_cb(void *priv, * * On enable, emits a series of address notifications for all * currently registered hosts. - * - * Must be called under rtnl_lock */ static int qeth_l2_dev2br_an_set(struct qeth_card *card, bool enable) { @@ -1289,16 +1287,19 @@ static void qeth_l2_dev2br_worker(struct work_struct *work) if (READ_ONCE(card->info.pnso_mode) == QETH_PNSO_NONE) goto free; - /* Potential re-config in progress, try again later: */ - if (!rtnl_trylock()) { - queue_delayed_work(card->event_wq, dwork, - msecs_to_jiffies(100)); - return; - } - if (!netif_device_present(card->dev)) - goto out_unlock; - if (data->ac_event.lost_event_mask) { + /* Potential re-config in progress, try again later: */ + if (!rtnl_trylock()) { + queue_delayed_work(card->event_wq, dwork, + msecs_to_jiffies(100)); + return; + } + + if (!netif_device_present(card->dev)) { + rtnl_unlock(); + goto free; + } + QETH_DBF_MESSAGE(3, "Address change notification overflow on device %x\n", CARD_DEVID(card)); @@ -1328,6 +1329,8 @@ static void qeth_l2_dev2br_worker(struct work_struct *work) "Address Notification resynced on device %x\n", CARD_DEVID(card)); } + + rtnl_unlock(); } else { for (i = 0; i < data->ac_event.num_entries; i++) { struct qeth_ipacmd_addr_change_entry *entry = @@ -1339,9 +1342,6 @@ static void qeth_l2_dev2br_worker(struct work_struct *work) } } -out_unlock: - rtnl_unlock(); - free: kfree(data); } @@ -2310,11 +2310,8 @@ static void qeth_l2_set_offline(struct qeth_card *card) card->state = CARD_STATE_DOWN; qeth_l2_set_pnso_mode(card, QETH_PNSO_NONE); - if (priv->brport_features & BR_LEARNING_SYNC) { - rtnl_lock(); + if (priv->brport_features & BR_LEARNING_SYNC) qeth_l2_dev2br_fdb_flush(card); - rtnl_unlock(); - } } /* Returns zero if the command is successfully "consumed" */ -- 2.17.1