wi(4) - polling(4) changes / DEVICE_POLLING

M. Warner Losh imp at bsdimp.com
Mon Apr 21 16:36:32 PDT 2003

In message: <20030421064717.B98117 at xorpc.icir.org>
            Luigi Rizzo <rizzo at icir.org> writes:
: if i remember well, the "wi" driver copies the packet from the card
: to the mbuf using programmed I/O. Switching to polling will just
: move the load under a different bucket (SYSTEM or IDLE instead
: of INTR) but not change the situation radically, and i
: doubt you will achieve significant performance improvements.

The wi driver does use PIO to move the data from the cards to memory.
Newer PCI and mini-pci cards support using DMA to do this, but there's
no support for that in the driver at the moment.

The wi cards are just damn expensive to talk to :-(.


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