This fixes a race during initialization with the NAPI softirq
processing by using an RCU approach.
This race was discovered when refill_skbs() was added to
the setup code.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
we could do one thing (see the patch below): i think it would be useful
to fill up the netlogging skb queue straight at initialization time.
Especially if netpoll is used for dumping alone, the system might not be
in a situation to fill up the queue at the point of crash, so better be
a bit more prepared and keep the pipeline filled.
[ I've modified this to be called earlier - mpm ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add limited retry logic to netpoll_send_skb
Each time we attempt to send, decrement our per-device retry counter.
On every successful send, we reset the counter.
We delay 50us between attempts with up to 20000 retries for a total of
1 second. After we've exhausted our retries, subsequent failed
attempts will try only once until reset by success.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor netpoll_send_skb restructuring
Restructure to avoid confusing goto and move some bits out of the
retry loop.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes an obvious deadlock in the netpoll code. netpoll_rx takes the
npinfo->rx_lock. netpoll_rx is also the only caller of arp_reply (through
__netpoll_rx). As such, it is not necessary to take this lock.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initialize npinfo->rx_flags. The way it stands now, this will have random
garbage, and so will incur a locking penalty even when an rx_hook isn't
registered and we are not active in the netpoll polling code.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch provides support for registering multiple netpoll clients to the
same network device. Only one of these clients may register an rx_hook,
however. In practice, this restriction has not been problematic. It is
worth mentioning, though, that the current design can be easily extended to
allow for the registration of multiple rx_hooks.
The basic idea of the patch is that the rx_np pointer in the netpoll_info
structure points to the struct netpoll that has rx_hook filled in. Aside
from this one case, there is no need for a pointer from the struct
net_device to an individual struct netpoll.
A lock is introduced to protect the setting and clearing of the np_rx
pointer. The pointer will only be cleared upon netpoll client module
removal, and the lock should be uncontested.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces a netpoll_info structure, which the struct net_device
will now point to instead of pointing to a struct netpoll. The reason for
this is two-fold: 1) fields such as the rx_flags, poll_owner, and poll_lock
should be maintained per net_device, not per netpoll; and 2) this is a first
step in providing support for multiple netpoll clients to register against the
same net_device.
The struct netpoll is now pointed to by the netpoll_info structure. As
such, the previous behaviour of the code is preserved.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
