From: Yongseok Koh <yskoh@mellanox.com>
To: adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com
Cc: dev@dpdk.org, Yongseok Koh <yskoh@mellanox.com>, stable@dpdk.org
Subject: [dpdk-dev] [PATCH] net/mlx5: fix deadlock of link status alarm
Date: Wed, 10 Jan 2018 09:46:49 -0800 [thread overview]
Message-ID: <20180110174649.33662-1-yskoh@mellanox.com> (raw)
If mlx5_dev_link_status_handler() is executed while canceling the alarm,
deadlock can happen because rte_eal_alarm_cancel() waits for all callbackes
to finish execution and both calls are protected by priv->lock.
Fixes: 198a3c339a8f ("mlx5: handle link status interrupts")
Cc: stable@dpdk.org
Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
drivers/net/mlx5/mlx5.h | 16 ++++++++++++++++
drivers/net/mlx5/mlx5_ethdev.c | 13 +++++++++----
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 8ee522069..e740a4e77 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -180,6 +180,22 @@ priv_lock(struct priv *priv)
}
/**
+ * Try to lock private structure to protect it from concurrent access in the
+ * control path.
+ *
+ * @param priv
+ * Pointer to private structure.
+ *
+ * @return
+ * 1 if the lock is successfully taken; 0 otherwise.
+ */
+static inline int
+priv_trylock(struct priv *priv)
+{
+ return rte_spinlock_trylock(&priv->lock);
+}
+
+/**
* Unlock private structure.
*
* @param priv
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 278a4dfc3..618d13d5f 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -1187,8 +1187,12 @@ mlx5_dev_link_status_handler(void *arg)
struct priv *priv = dev->data->dev_private;
int ret;
- priv_lock(priv);
- assert(priv->pending_alarm == 1);
+ while (!priv_trylock(priv)) {
+ /* Alarm is being canceled. */
+ if (priv->pending_alarm == 0)
+ return;
+ rte_pause();
+ }
priv->pending_alarm = 0;
ret = priv_link_status_update(priv);
priv_unlock(priv);
@@ -1258,9 +1262,10 @@ priv_dev_interrupt_handler_uninstall(struct priv *priv, struct rte_eth_dev *dev)
if (priv->primary_socket)
rte_intr_callback_unregister(&priv->intr_handle_socket,
mlx5_dev_handler_socket, dev);
- if (priv->pending_alarm)
+ if (priv->pending_alarm) {
+ priv->pending_alarm = 0;
rte_eal_alarm_cancel(mlx5_dev_link_status_handler, dev);
- priv->pending_alarm = 0;
+ }
priv->intr_handle.fd = 0;
priv->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
priv->intr_handle_socket.fd = 0;
--
2.11.0
next reply other threads:[~2018-01-10 17:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-10 17:46 Yongseok Koh [this message]
2018-01-15 6:45 ` [dpdk-dev] [dpdk-stable] " Shahaf Shuler
-- strict thread matches above, loose matches on Subject: below --
2018-01-09 9:09 [dpdk-dev] " Yongseok Koh
2018-01-10 10:11 ` Nelio Laranjeiro
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180110174649.33662-1-yskoh@mellanox.com \
--to=yskoh@mellanox.com \
--cc=adrien.mazarguil@6wind.com \
--cc=dev@dpdk.org \
--cc=nelio.laranjeiro@6wind.com \
--cc=stable@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).