Michael S. Tsirkin 92898522e3 IB/mthca: prevent event queue overrun ... I am seeing EQ overruns in SDP stress tests: if the CQ completion handler arms a CQ, this could generate more EQEs, so that EQ will never get empty and consumer index will never get updated. This is similiar to what we have with command interface: /* * cmd_event() may add more commands. * The card will think the queue has overflowed if * we don't tell it we've been processing events. */ However, for completion events, we *don't* want to update the consumer index on each event. So, perform EQ doorbell coalescing: allocate EQs with some spare EQEs, and update once we run out of them. The value 0x80 was selected to avoid any performance impact. Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>		2006-01-09 14:04:40 -08:00
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mthca	IB/mthca: prevent event queue overrun	2006-01-09 14:04:40 -08:00