diff options
author | Eric Dumazet <edumazet@google.com> | 2013-10-30 13:10:44 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2013-11-03 23:19:00 -0500 |
commit | 74d332c13b2148ae934ea94dac1745ae92efe8e5 (patch) | |
tree | 4f8f287774deaba28fa4c85d085d587ae7515aaf | |
parent | b397f99921827e114d7f5600447e172a99c50165 (diff) | |
download | op-kernel-dev-74d332c13b2148ae934ea94dac1745ae92efe8e5.zip op-kernel-dev-74d332c13b2148ae934ea94dac1745ae92efe8e5.tar.gz |
net: extend net_device allocation to vmalloc()
Joby Poriyath provided a xen-netback patch to reduce the size of
xenvif structure as some netdev allocation could fail under
memory pressure/fragmentation.
This patch is handling the problem at the core level, allowing
any netdev structures to use vmalloc() if kmalloc() failed.
As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Joby Poriyath <joby.poriyath@citrix.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | Documentation/networking/netdevices.txt | 10 | ||||
-rw-r--r-- | include/linux/netdevice.h | 1 | ||||
-rw-r--r-- | net/core/dev.c | 22 | ||||
-rw-r--r-- | net/core/net-sysfs.c | 2 |
4 files changed, 24 insertions, 11 deletions
diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt index c7ecc70..0b1cf6b 100644 --- a/Documentation/networking/netdevices.txt +++ b/Documentation/networking/netdevices.txt @@ -10,12 +10,12 @@ network devices. struct net_device allocation rules ================================== Network device structures need to persist even after module is unloaded and -must be allocated with kmalloc. If device has registered successfully, -it will be freed on last use by free_netdev. This is required to handle the -pathologic case cleanly (example: rmmod mydriver </sys/class/net/myeth/mtu ) +must be allocated with alloc_netdev_mqs() and friends. +If device has registered successfully, it will be freed on last use +by free_netdev(). This is required to handle the pathologic case cleanly +(example: rmmod mydriver </sys/class/net/myeth/mtu ) -There are routines in net_init.c to handle the common cases of -alloc_etherdev, alloc_netdev. These reserve extra space for driver +alloc_netdev_mqs()/alloc_netdev() reserve extra space for driver private data which gets freed when the network device is freed. If separately allocated data is attached to the network device (netdev_priv(dev)) then it is up to the module exit handler to free that. diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index cb1d918..e6353ca 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1800,6 +1800,7 @@ static inline void unregister_netdevice(struct net_device *dev) int netdev_refcnt_read(const struct net_device *dev); void free_netdev(struct net_device *dev); +void netdev_freemem(struct net_device *dev); void synchronize_net(void); int init_dummy_netdev(struct net_device *dev); diff --git a/net/core/dev.c b/net/core/dev.c index 0054c8c..0e61365 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6196,6 +6196,16 @@ void netdev_set_default_ethtool_ops(struct net_device *dev, } EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops); +void netdev_freemem(struct net_device *dev) +{ + char *addr = (char *)dev - dev->padded; + + if (is_vmalloc_addr(addr)) + vfree(addr); + else + kfree(addr); +} + /** * alloc_netdev_mqs - allocate network device * @sizeof_priv: size of private data to allocate space for @@ -6239,7 +6249,9 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, /* ensure 32-byte alignment of whole construct */ alloc_size += NETDEV_ALIGN - 1; - p = kzalloc(alloc_size, GFP_KERNEL); + p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); + if (!p) + p = vzalloc(alloc_size); if (!p) return NULL; @@ -6248,7 +6260,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, dev->pcpu_refcnt = alloc_percpu(int); if (!dev->pcpu_refcnt) - goto free_p; + goto free_dev; if (dev_addr_init(dev)) goto free_pcpu; @@ -6301,8 +6313,8 @@ free_pcpu: kfree(dev->_rx); #endif -free_p: - kfree(p); +free_dev: + netdev_freemem(dev); return NULL; } EXPORT_SYMBOL(alloc_netdev_mqs); @@ -6339,7 +6351,7 @@ void free_netdev(struct net_device *dev) /* Compatibility with error handling in drivers */ if (dev->reg_state == NETREG_UNINITIALIZED) { - kfree((char *)dev - dev->padded); + netdev_freemem(dev); return; } diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index d954b56..d03f2c9 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1263,7 +1263,7 @@ static void netdev_release(struct device *d) BUG_ON(dev->reg_state != NETREG_RELEASED); kfree(dev->ifalias); - kfree((char *)dev - dev->padded); + netdev_freemem(dev); } static const void *net_namespace(struct device *d) |