Eric Dumazet 564824b0c5 net: allocate skbs on local node ... commit b30973f877 (node-aware skb allocation) spread a wrong habit of allocating net drivers skbs on a given memory node : The one closest to the NIC hardware. This is wrong because as soon as we try to scale network stack, we need to use many cpus to handle traffic and hit slub/slab management on cross-node allocations/frees when these cpus have to alloc/free skbs bound to a central node. skb allocated in RX path are ephemeral, they have a very short lifetime : Extra cost to maintain NUMA affinity is too expensive. What appeared as a nice idea four years ago is in fact a bad one. In 2010, NIC hardwares are multiqueue, or we use RPS to spread the load, and two 10Gb NIC might deliver more than 28 million packets per second, needing all the available cpus. Cost of cross-node handling in network and vm stacks outperforms the small benefit hardware had when doing its DMA transfert in its 'local' memory node at RX time. Even trying to differentiate the two allocations done for one skb (the sk_buff on local node, the data part on NIC hardware node) is not enough to bring good performance. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2010-10-16 11:13:19 -07:00
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acpi	ACPI: Fix typos	2010-09-28 21:38:19 -04:00
asm-generic	gpio: doc updates	2010-09-09 18:57:24 -07:00
crypto
drm	drm: Hold the mutex when dropping the last GEM reference (v2)	2010-10-01 21:08:45 +10:00
keys
linux	net: allocate skbs on local node	2010-10-16 11:13:19 -07:00
math-emu
media
mtd
net	Phonet: 'connect' socket implementation for Pipe controller	2010-10-13 14:40:34 -07:00
pcmcia
rdma
rxrpc
scsi
sound
trace
video
xen
Kbuild