diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2025-08-12 14:43:08 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-08-12 14:43:08 +0200 |
| commit | 74078816f8b937afbcc7c2991977527b2c77463d (patch) | |
| tree | dc9a380c7e7a58f7e8e720d91efe752f933f6afa /net | |
| parent | e93f7af148222303c4632318536c0f649b4ee5b1 (diff) | |
| parent | b3fc08ab9a565efb42fe08be046a0d203b82cdb8 (diff) | |
Merge branch 'net-prevent-deadlocks-and-mis-configuration-with-per-napi-threaded-config'
Jakub Kicinski says:
====================
net: prevent deadlocks and mis-configuration with per-NAPI threaded config
Running the test added with a recent fix on a driver with persistent
NAPI config leads to a deadlock. The deadlock is fixed by patch 3,
patch 2 is I think a more fundamental problem with the way we
implemented the config.
I hope the fix makes sense, my own thinking is definitely colored
by my preference (IOW how the per-queue config RFC was implemented).
v1: https://lore.kernel.org/20250808014952.724762-1-kuba@kernel.org
====================
Link: https://patch.msgid.link/20250809001205.1147153-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 12 | ||||
| -rw-r--r-- | net/core/dev.h | 8 |
2 files changed, 17 insertions, 3 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 68dc47d7e700..5a3c0f40a93f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6999,7 +6999,7 @@ int netif_set_threaded(struct net_device *dev, enum netdev_napi_threaded threaded) { struct napi_struct *napi; - int err = 0; + int i, err = 0; netdev_assert_locked_or_invisible(dev); @@ -7021,6 +7021,10 @@ int netif_set_threaded(struct net_device *dev, list_for_each_entry(napi, &dev->napi_list, dev_list) WARN_ON_ONCE(napi_set_threaded(napi, threaded)); + /* Override the config for all NAPIs even if currently not listed */ + for (i = 0; i < dev->num_napi_configs; i++) + dev->napi_config[i].threaded = threaded; + return err; } @@ -7353,8 +7357,9 @@ void netif_napi_add_weight_locked(struct net_device *dev, * Clear dev->threaded if kthread creation failed so that * threaded mode will not be enabled in napi_enable(). */ - if (dev->threaded && napi_kthread_create(napi)) - dev->threaded = NETDEV_NAPI_THREADED_DISABLED; + if (napi_get_threaded_config(dev, napi)) + if (napi_kthread_create(napi)) + dev->threaded = NETDEV_NAPI_THREADED_DISABLED; netif_napi_set_irq_locked(napi, -1); } EXPORT_SYMBOL(netif_napi_add_weight_locked); @@ -11873,6 +11878,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, goto free_all; dev->cfg_pending = dev->cfg; + dev->num_napi_configs = maxqs; napi_config_sz = array_size(maxqs, sizeof(*dev->napi_config)); dev->napi_config = kvzalloc(napi_config_sz, GFP_KERNEL_ACCOUNT); if (!dev->napi_config) diff --git a/net/core/dev.h b/net/core/dev.h index ab69edc0c3e3..d6b08d435479 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -323,6 +323,14 @@ static inline enum netdev_napi_threaded napi_get_threaded(struct napi_struct *n) return NETDEV_NAPI_THREADED_DISABLED; } +static inline enum netdev_napi_threaded +napi_get_threaded_config(struct net_device *dev, struct napi_struct *n) +{ + if (n->config) + return n->config->threaded; + return dev->threaded; +} + int napi_set_threaded(struct napi_struct *n, enum netdev_napi_threaded threaded); |