Change Details

Make sure all network drivers apply the EPOCH before forwarding network packets into the network stack. Several drivers have timers, taskqueues and other mechanisms that input network packets. This was not covered by the initial sweep that was done. Pointy hat: glebius Sponsored by: Mellanox Technologies

Widen EPOCH(9) usage in network drivers. Make sure network drivers enter and exit the EPOCH(9) before forwarding network packets to the network stack. This is part of widening the EPOCH(9) usage so that entering and exiting the EPOCH(9) at every packet input to the network stack can be avoided. This patch address the shortcomings of r357004, that many network drivers have timers, taskqueues and even own threads that input IP packets, and not only interrupt threads. Two convenience macros NET_EPOCH_WRAP() and NET_EPOCH_WRAP_RET() have been added to minimize the amount of patching needed in each network driver. This patch should unbreak most of the USB WLAN drivers among others. Each network driver is now responsible for entering and exiting the EPOCH(9) before calling the if_input method of struct ifnet. The only exception is when debugnet is activated. Then EPOCH(9) is not required. Also netisr_queue(9) can be called outside an EPOCH(9) section, which is used by sppp_input() for example. Typically the coalesching parameters or interrupt moderation settings in existing drivers now indirectly control how frequently the EPOCH(9) is entered and exited. The more packets that are input at a time, the more time the epoch_wait(9) function may need which can lead to temporarily increased memory usage, because of structures waiting to be freed by an epoch_call(9). Sponsored by: Mellanox Technologies

Make sure all network drivers apply theWiden EPOCH before forwarding(9) usage in network packets into the network stackdrivers. SeveralMake sure network drivers have timers,enter and exit the EPOCH(9) before forwarding network packets to the network stack. taskqueues and other mechanisms that input network packets. This was not covered by the initial sweep that was doneThis is part of widening the EPOCH(9) usage so that entering and exiting the EPOCH(9) at every packet input to the network stack can be avoided. Pointy hat: glebiusThis patch address the shortcomings of r357004, that many network drivers have timers, taskqueues and even own threads that input IP packets, and not only interrupt threads. Two convenience macros NET_EPOCH_WRAP() and NET_EPOCH_WRAP_RET() have been added to minimize the amount of patching needed in each network driver. This patch should unbreak most of the USB WLAN drivers among others. Each network driver is now responsible for entering and exiting the EPOCH(9) before calling the if_input method of struct ifnet. The only exception is when debugnet is activated. Then EPOCH(9) is not required. Also netisr_queue(9) can be called outside an EPOCH(9) section, which is used by sppp_input() for example. Typically the coalesching parameters or interrupt moderation settings in existing drivers now indirectly control how frequently the EPOCH(9) is entered and exited. The more packets that are input at a time, the more time the epoch_wait(9) function may need which can lead to temporarily increased memory usage, because of structures waiting to be freed by an epoch_call(9). Sponsored by: Mellanox Technologies