[Xen-devel] [PATCH] netback: tx stalls with default credit_bytes

["Kirk Allan" <kallan@xxxxxxxxxx>]

This situation happens when netif->credit_bytes is using the default of ~0UL, 
effectively -1.  Once the current tx packet size is greater than the 
netif->remaining_credit, transmits will stall until netif->remaining_credit 
wraps back to ~0UL in tx_add_credit().  The min(netif->remaining_credit + 
netif->credit_bytes, max_burst) has the effect of decrementing 
netif->remaining_credit by 1.  The min will continually be less than the 
current tx packet size until tx_add_credit() is called packet size times which 
allows netif->remaining_credit to wrap back to ~0UL.

The patch splits the min() into two steps to eliminate the case of adding by -1.

signed-of-by Kirk Allan <kallan@xxxxxxxxxx>

Attachment: netback.diff
Description: Binary data

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