Rusty Russell a écrit :
> Various drivers do skb_orphan() because they do not free transmitted
> skbs in a timely manner (causing apps which hit their socket limits to
> stall, socket close to hang, etc.).
>
> DaveM points out that there are advantages to doing it generally (it's
> more likely to
VIRTIO_F_NOTIFY_ON_EMPTY indicates to the Guest that we will hit them with
an interrupt every time the xmit queue is emptied.
Because it results in lots of tx interrupts, modern Guests probably don't
want it, so let's only force it when they accept the option.
Signed-off-by: Rusty Russell
---
D
This effectively reverts 99ffc696d10b28580fe93441d627cf290ac4484c
"virtio: wean net driver off NETDEV_TX_BUSY".
The complexity of queuing an skb (setting a tasklet to re-xmit) is
questionable, especially once we get rid of the other reason for the
tasklet in the next patch.
If the skb won't fit
The virtio_net driver is complicated by the two methods of freeing old
xmit buffers (in addition to freeing old ones at the start of the xmit
path).
The original code used a 1/10 second timer attached to xmit_free(),
reset on every xmit. Before we orphaned skbs on xmit, the
transmitting userspac
Various drivers do skb_orphan() because they do not free transmitted
skbs in a timely manner (causing apps which hit their socket limits to
stall, socket close to hang, etc.).
DaveM points out that there are advantages to doing it generally (it's
more likely to be on same CPU than after xmit), and
