netvsc: optimize receive completions
Optimize how receive completion ring are managed.
* Allocate only as many slots as needed for all buffers from host
* Allocate before setting up sub channel for better error detection
* Don't need to keep copy of initial receive section message
* Precompute the watermark for when receive flushing is needed
* Replace division with conditional test
* Replace atomic per-device variable with per-channel check.
* Handle corner case where receive completion send
fails if ring buffer to host is full.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3 files changed