[patch net-next v4 3/9] devlink: send notifications only if there are listeners

Jiri Pirko
2023-11-23T18:15:54Z

From: Jiri Pirko <jiri@nvidia.com>

Introduce devlink_nl_notify_need() helper and using it to check at the
beginning of notification functions to avoid overhead of composing
notification messages in case nobody listens.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
net/devlink/dev.c | 5 ++++-
net/devlink/devl_internal.h | 6 ++++++
net/devlink/health.c | 3 +++
net/devlink/linecard.c | 2 +-
net/devlink/param.c | 2 +-
net/devlink/port.c | 2 +-
net/devlink/rate.c | 2 +-
net/devlink/region.c | 2 +-
net/devlink/trap.c | 6 +++---
9 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 7c7517e26862..46407689ef70 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -204,6 +204,9 @@ static void devlink_notify(struct devlink *devlink, enum devlink_command cmd)
WARN_ON(cmd != DEVLINK_CMD_NEW && cmd != DEVLINK_CMD_DEL);
WARN_ON(!devl_is_registered(devlink));

+ if (!devlink_nl_notify_need(devlink))
+ return;
+
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return;
@@ -985,7 +988,7 @@ static void __devlink_flash_update_notify(struct devlink *devlink,
cmd != DEVLINK_CMD_FLASH_UPDATE_END &&
cmd != DEVLINK_CMD_FLASH_UPDATE_STATUS);

- if (!devl_is_registered(devlink))
+ if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 59ae4761d10a..510990de094e 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -185,6 +185,12 @@ int devlink_nl_put_nested_handle(struct sk_buff *msg, struct net *net,
struct devlink *devlink, int attrtype);
int devlink_nl_msg_reply_and_new(struct sk_buff **msg, struct genl_info *info);

+static inline bool devlink_nl_notify_need(struct devlink *devlink)
+{
+ return genl_has_listeners(&devlink_nl_family, devlink_net(devlink),
+ DEVLINK_MCGRP_CONFIG);
+}
+
/* Notify */
void devlink_notify_register(struct devlink *devlink);
void devlink_notify_unregister(struct devlink *devlink);
diff --git a/net/devlink/health.c b/net/devlink/health.c
index 71ae121dc739..0795dcf22ca8 100644
--- a/net/devlink/health.c
+++ b/net/devlink/health.c
@@ -496,6 +496,9 @@ static void devlink_recover_notify(struct devlink_health_reporter *reporter,
WARN_ON(cmd != DEVLINK_CMD_HEALTH_REPORTER_RECOVER);
ASSERT_DEVLINK_REGISTERED(devlink);

+ if (!devlink_nl_notify_need(devlink))
+ return;
+
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return;
diff --git a/net/devlink/linecard.c b/net/devlink/linecard.c
index 9d080ac1734b..45b36975ee6f 100644
--- a/net/devlink/linecard.c
+++ b/net/devlink/linecard.c
@@ -136,7 +136,7 @@ static void devlink_linecard_notify(struct devlink_linecard *linecard,
WARN_ON(cmd != DEVLINK_CMD_LINECARD_NEW &&
cmd != DEVLINK_CMD_LINECARD_DEL);

- if (!__devl_is_registered(devlink))
+ if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/param.c b/net/devlink/param.c
index d74df09311a9..6bb6aee5d937 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -343,7 +343,7 @@ static void devlink_param_notify(struct devlink *devlink,
* will replay the notifications if the params are added/removed
* outside of the lifetime of the instance.
*/
- if (!devl_is_registered(devlink))
+ if (!devlink_nl_notify_need(devlink) || !devl_is_registered(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/port.c b/net/devlink/port.c
index f229a8699214..32f4d0331e63 100644
--- a/net/devlink/port.c
+++ b/net/devlink/port.c
@@ -512,7 +512,7 @@ static void devlink_port_notify(struct devlink_port *devlink_port,

WARN_ON(cmd != DEVLINK_CMD_PORT_NEW && cmd != DEVLINK_CMD_PORT_DEL);

- if (!__devl_is_registered(devlink))
+ if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index e2190cf22beb..0371a2dd3e0a 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -146,7 +146,7 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate,

WARN_ON(cmd != DEVLINK_CMD_RATE_NEW && cmd != DEVLINK_CMD_RATE_DEL);

- if (!devl_is_registered(devlink))
+ if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/region.c b/net/devlink/region.c
index b65181aa269a..bf61312f64bd 100644
--- a/net/devlink/region.c
+++ b/net/devlink/region.c
@@ -235,7 +235,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,

WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);

- if (!__devl_is_registered(devlink))
+ if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
diff --git a/net/devlink/trap.c b/net/devlink/trap.c
index 908085e2c990..3ca1ca7e2e64 100644
--- a/net/devlink/trap.c
+++ b/net/devlink/trap.c
@@ -1174,7 +1174,7 @@ devlink_trap_group_notify(struct devlink *devlink,
WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_GROUP_NEW &&
cmd != DEVLINK_CMD_TRAP_GROUP_DEL);

- if (!devl_is_registered(devlink))
+ if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1236,7 +1236,7 @@ static void devlink_trap_notify(struct devlink *devlink,
WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_NEW &&
cmd != DEVLINK_CMD_TRAP_DEL);

- if (!devl_is_registered(devlink))
+ if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1713,7 +1713,7 @@ devlink_trap_policer_notify(struct devlink *devlink,
WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_POLICER_NEW &&
cmd != DEVLINK_CMD_TRAP_POLICER_DEL);

- if (!devl_is_registered(devlink))
+ if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;

msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
--
2.41.0