• Eric Dumazet's avatar
    forcedeth: Fix NAPI race. · 78c29bd9
    Eric Dumazet authored
    Eric Dumazet a écrit :
    > Ingo Molnar a écrit :
    >>> The following changes since commit 52989765:
    >>>   Linus Torvalds (1):
    >>>         Merge git://git.kernel.org/.../davem/net-2.6
    
    > >>> are available in the git repository at:
    
    >>>   master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6.git master
    >> Hm, something in this lot quickly wrecked networking here - see the
    >> tx timeout dump below. It starts with:
    >>
    >> [  351.004596] WARNING: at net/sched/sch_generic.c:246 dev_watchdog+0x10b/0x19c()
    >> [  351.011815] Hardware name: System Product Name
    >> [  351.016220] NETDEV WATCHDOG: eth0 (forcedeth): transmit queue 0 timed out
    >>
    >> Config attached. Unfortunately i've got no time to do bisection
    >> today.
    >
    >
    >
    > forcedeth might have a problem, in its netif_wake_queue() logic, but
    > I could not see why a recent patch could make this problem visible now.
    >
    > CPU0/1: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ stepping 02
    > is not a new cpu either :)
    >
    > forcedeth uses an internal tx_stop without appropriate barrier.
    >
    > Could you try following patch ?
    >
    > (random guess as I dont have much time right now)
    
    We might have a race in napi_schedule(), leaving interrupts disabled forever.
    I cannot test this patch, I dont have the hardware...
    Tested-by: default avatarIngo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    78c29bd9
forcedeth.c 193 KB