diff options
| author | Maxime Chevallier <maxime.chevallier@bootlin.com> | 2026-10-29 16:31:29 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-10-30 15:47:58 -0700 |
| commit | 8dc87fc5d6a0eb337744737008177342a708bf36 (patch) | |
| tree | 1f136e04c365b7c456d44fd034cc8c96f1ea0202 /include | |
| parent | ed6c53b27be492643da2017c6f8e2732be5edf1a (diff) | |
net: Use a dedicated flag to track disabled napi instances
Trying to disable the napi threaded state while the napi instance is
disabled will hang forever in napi_stop_kthread(), as it waits for
NAPIF_STATE_SCHED_THREADED to clear.
This won't happen until the next ____napi_schedule() call, which won't
happen as it's disabled.
This happens in 2 instances :
- Drivers that create but don't use napi instances (stmmac's rxtx napi
for AF_XDP for example), here it's a driver bug
- Drivers that create their napi instances in .probe(). Here, setting
threaded off while the interface is down will hang :
ip link set eth0 down
echo 1 > /sys/class/net/eth0/threaded
echo 0 > /sys/class/net/eth0/threaded
-> hang
Checking on netif_running() isn't enough, as napi instances may be
transiently disabled when changing the MTU for example, let's use a
dedicated flag to track if the instance is disabled.
This allows immediately disabling the kthread when the instance is
disabled.
This was tested on mvpp2 (probe-time napi_add) and stmmac.
Fixes: 689883de94dd ("net: stop napi kthreads when THREADED napi is disabled")
Tested-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20261029153130.121204-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c0ae442c4344..435be7880d7e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -440,6 +440,7 @@ enum { NAPI_STATE_HAS_NOTIFIER, /* Napi has an IRQ notifier */ NAPI_STATE_THREADED_BUSY_POLL, /* The threaded NAPI poller will busy poll */ NAPI_STATE_PERCPU, /* NAPI handler is run per-CPU - incompatible with threaded mode */ + NAPI_STATE_DISABLED, /* NAPI is disabled */ }; enum { @@ -456,6 +457,7 @@ enum { NAPIF_STATE_HAS_NOTIFIER = BIT(NAPI_STATE_HAS_NOTIFIER), NAPIF_STATE_THREADED_BUSY_POLL = BIT(NAPI_STATE_THREADED_BUSY_POLL), NAPIF_STATE_PERCPU = BIT(NAPI_STATE_PERCPU), + NAPIF_STATE_DISABLED = BIT(NAPI_STATE_DISABLED), }; enum gro_result { |