I just updated Documentation/networking/netdevices.txt locally to the
attached file, which describes the synchronization rules for net drivers
in the 2.4.x and 2.5.x kernels. (Astute readers will notice a striking
similarity to 2.2.x locking rules as well)
Comments and corrections to the attached doc requested. I realize it's
not much right now, but this is core info I want to make sure is
correct, and that everyone agrees on.
Thanks to Robert Olsson for a pointer about dev->poll().
Future notes: this doc will hopefully expand in time to describe not
only the netdevice API but also standard ethernet and net driver
practices. Patches welcome!
Jeff
Network Devices, the Kernel, and You!
Introduction
============
The following is a random collection of documentation regarding
network devices.
struct net_device synchronization rules
=======================================
dev->open:
Synchronization: rtnl_lock() semaphore.
Context: process
dev->stop:
Synchronization: rtnl_lock() semaphore.
Context: process
Notes: netif_running() is guaranteed false when this is called
dev->do_ioctl:
Synchronization: rtnl_lock() semaphore.
Context: process
dev->get_stats:
Synchronization: dev_base_lock rwlock.
Context: nominally process, but don't sleep inside an rwlock
dev->hard_start_xmit:
Synchronization: dev->xmit_lock spinlock.
Context: BHs disabled
dev->tx_timeout:
Synchronization: dev->xmit_lock spinlock.
Context: BHs disabled
dev->set_multicast_list:
Synchronization: dev->xmit_lock spinlock.
Context: BHs disabled
dev->poll:
Synchronization: __LINK_STATE_RX_SCHED bit in dev->state. See
dev_close code and comments in net/core/dev.c for more info.
Context: softirq
-
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This archive was generated by hypermail 2b29 : Sat Dec 07 2002 - 22:00:15 EST