devlink: send notifications only if there are listeners

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>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 3fe93c8..63fe3e0 100644 (file)
--- 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;
@@ -999,7 +1002,7 @@ 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 59ae476..510990d 100644 (file)
--- 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 71ae121..0795dcf 100644 (file)
--- 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 9d080ac..45b3697 100644 (file)
--- 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 d74df09..7516b52 100644 (file)
--- 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 (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
                return;
 
        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

diff --git a/net/devlink/port.c b/net/devlink/port.c
index f229a86..32f4d03 100644 (file)
--- 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 e2190cf..0371a2d 100644 (file)
--- 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 b65181a..bf61312 100644 (file)
--- 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 908085e..3ca1ca7 100644 (file)
--- 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);