1. 18 6月, 2006 1 次提交
    • H
      [NET]: Add netif_tx_lock · 932ff279
      Herbert Xu 提交于
      Various drivers use xmit_lock internally to synchronise with their
      transmission routines.  They do so without setting xmit_lock_owner.
      This is fine as long as netpoll is not in use.
      
      With netpoll it is possible for deadlocks to occur if xmit_lock_owner
      isn't set.  This is because if a printk occurs while xmit_lock is held
      and xmit_lock_owner is not set can cause netpoll to attempt to take
      xmit_lock recursively.
      
      While it is possible to resolve this by getting netpoll to use
      trylock, it is suboptimal because netpoll's sole objective is to
      maximise the chance of getting the printk out on the wire.  So
      delaying or dropping the message is to be avoided as much as possible.
      
      So the only alternative is to always set xmit_lock_owner.  The
      following patch does this by introducing the netif_tx_lock family of
      functions that take care of setting/unsetting xmit_lock_owner.
      
      I renamed xmit_lock to _xmit_lock to indicate that it should not be
      used directly.  I didn't provide irq versions of the netif_tx_lock
      functions since xmit_lock is meant to be a BH-disabling lock.
      
      This is pretty much a straight text substitution except for a small
      bug fix in winbond.  It currently uses
      netif_stop_queue/spin_unlock_wait to stop transmission.  This is
      unsafe as an IRQ can potentially wake up the queue.  So it is safer to
      use netif_tx_disable.
      
      The hamradio bits used spin_lock_irq but it is unnecessary as
      xmit_lock must never be taken in an IRQ handler.
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      932ff279
  2. 20 5月, 2006 1 次提交
  3. 27 1月, 2006 1 次提交
  4. 29 6月, 2005 1 次提交
    • D
      [NET]: Remove gratuitous use of skb->tail in network drivers. · 689be439
      David S. Miller 提交于
      Many drivers use skb->tail unnecessarily.
      
      In these situations, the code roughly looks like:
      
      	dev = dev_alloc_skb(...);
      
      	[optional] skb_reserve(skb, ...);
      
      	... skb->tail ...
      
      But even if the skb_reserve() happens, skb->data equals
      skb->tail.  So it doesn't make any sense to use anything
      other than skb->data in these cases.
      
      Another case was the s2io.c driver directly mucking with
      the skb->data and skb->tail pointers.  It really just wanted
      to do an skb_reserve(), so that's what the code was changed
      to do instead.
      
      Another reason I'm making this change as it allows some SKB
      cleanups I have planned simpler to merge.  In those cleanups,
      skb->head, skb->tail, and skb->end pointers are removed, and
      replaced with skb->head_room and skb->tail_room integers.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Acked-by: NJeff Garzik <jgarzik@pobox.com>
      689be439
  5. 13 5月, 2005 1 次提交
  6. 17 4月, 2005 2 次提交