From: Ido Schimmel <idosch@idosch.org>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, nhorman@tuxdriver.com, dsahern@gmail.com,
roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com,
jakub.kicinski@netronome.com, toke@redhat.com,
andy@greyhouse.net, f.fainelli@gmail.com, andrew@lunn.ch,
vivien.didelot@gmail.com, mlxsw@mellanox.com,
Ido Schimmel <idosch@mellanox.com>
Subject: [RFC PATCH net-next 03/12] drop_monitor: Document scope of spinlock
Date: Mon, 22 Jul 2019 21:31:25 +0300 [thread overview]
Message-ID: <20190722183134.14516-4-idosch@idosch.org> (raw)
In-Reply-To: <20190722183134.14516-1-idosch@idosch.org>
From: Ido Schimmel <idosch@mellanox.com>
While 'per_cpu_dm_data' is a per-CPU variable, its 'skb' and
'send_timer' fields can be accessed concurrently by the CPU sending the
netlink notification to user space from the workqueue and the CPU
tracing kfree_skb(). This spinlock is meant to protect against that.
Document its scope and suppress the checkpatch message "spinlock_t
definition without comment".
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
net/core/drop_monitor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 000ec8b66d1e..35d31b007da4 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -52,7 +52,7 @@ static int trace_state = TRACE_OFF;
static DEFINE_MUTEX(net_dm_mutex);
struct per_cpu_dm_data {
- spinlock_t lock;
+ spinlock_t lock; /* Protects 'skb' and 'send_timer' */
struct sk_buff *skb;
struct work_struct dm_alert_work;
struct timer_list send_timer;
--
2.21.0
next prev parent reply other threads:[~2019-07-22 18:33 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 18:31 [RFC PATCH net-next 00/12] drop_monitor: Capture dropped packets and metadata Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 01/12] drop_monitor: Use correct error code Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 02/12] drop_monitor: Rename and document scope of mutex Ido Schimmel
2019-07-22 18:31 ` Ido Schimmel [this message]
2019-07-22 18:31 ` [RFC PATCH net-next 04/12] drop_monitor: Avoid multiple blank lines Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 05/12] drop_monitor: Add extack support Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 06/12] drop_monitor: Use pre_doit / post_doit hooks Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 07/12] drop_monitor: Split tracing enable / disable to different functions Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 08/12] drop_monitor: Initialize timer and work item upon tracing enable Ido Schimmel
2019-07-24 9:01 ` Jiri Pirko
2019-07-24 17:02 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 09/12] drop_monitor: Require CAP_NET_ADMIN for drop monitor configuration Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 10/12] drop_monitor: Add packet alert mode Ido Schimmel
2019-07-23 12:43 ` Neil Horman
2019-07-23 14:16 ` Ido Schimmel
2019-07-23 15:14 ` Neil Horman
2019-07-24 7:10 ` Ido Schimmel
2019-07-24 12:53 ` Jiri Pirko
2019-07-24 16:57 ` Ido Schimmel
2019-07-29 9:52 ` [drop_monitor] 98ffbd6cd2: will-it-scale.per_thread_ops -17.5% regression kernel test robot
2019-08-05 11:56 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 11/12] drop_monitor: Allow truncation of dropped packets Ido Schimmel
[not found] ` <20190724125537.GC2225@nanopsycho>
2019-07-24 16:49 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 12/12] drop_monitor: Add a command to query current configuration Ido Schimmel
2019-07-22 19:43 ` [RFC PATCH net-next 00/12] drop_monitor: Capture dropped packets and metadata Toke Høiland-Jørgensen
2019-07-23 6:46 ` Ido Schimmel
2019-07-23 12:17 ` Toke Høiland-Jørgensen
2019-07-23 15:14 ` Ido Schimmel
2019-07-23 15:47 ` David Ahern
2019-07-24 7:57 ` Ido Schimmel
2019-07-23 16:08 ` Toke Høiland-Jørgensen
2019-07-24 8:10 ` Ido Schimmel
2019-07-24 9:51 ` Toke Høiland-Jørgensen
2019-07-24 12:58 ` Jiri Pirko
2019-07-24 16:48 ` Ido Schimmel
2019-07-24 22:48 ` David Miller
2019-07-24 15:15 ` Jiri Pirko
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