Messages in this thread | | | Date | Tue, 13 Sep 2005 09:35:14 -0700 | From | Ben Greear <> | Subject | Re: [patch 7/11] net: Use bigrefs for net_device.refcount |
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Stephen Hemminger wrote: > On Tue, 13 Sep 2005 09:10:12 -0700 > Ravikiran G Thirumalai <kiran@scalex86.org> wrote: > > >>The net_device has a refcnt used to keep track of it's uses. >>This is used at the time of unregistering the network device >>(module unloading ..) (see netdev_wait_allrefs) . >>For loopback_dev , this refcnt increment/decrement is causing >>unnecessary traffic on the interlink for NUMA system >>affecting it's performance. This patch improves tbench numbers by 6% on a >>8way x86 Xeon (x445). >> > > > Since when is bringing a network device up/down performance critical?
We grab and drop a reference for each poll of a device, roughly.
See dev_hold in _netif_rx_schedule(struct net_device *dev) in include/netdevice.h, for instance.
Thanks, Ben
-- Ben Greear <greearb@candelatech.com> Candela Technologies Inc http://www.candelatech.com
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