Messages in this thread Patch in this message | | | Date | Thu, 02 Jul 2009 12:13:24 -0400 | From | Ayaz Abdulla <> | Subject | Re: [GIT]: Networking |
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Eric Dumazet wrote: > Eric Dumazet a écrit : > >>Ingo Molnar a écrit : >> >>>>The following changes since commit 52989765629e7d182b4f146050ebba0abf2cb0b7: >>>> 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) > > > Oh well this patch was soooo stupid, sorry Ingo. > > > We might have a race in napi_schedule(), leaving interrupts disabled forever. > I cannot test this patch, I dont have the hardware... > > Thanks > > diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c > index 1094d29..3b4e076 100644 > --- a/drivers/net/forcedeth.c > +++ b/drivers/net/forcedeth.c > @@ -3514,11 +3514,13 @@ static irqreturn_t nv_nic_irq(int foo, void *data) > nv_msi_workaround(np); > > #ifdef CONFIG_FORCEDETH_NAPI > - napi_schedule(&np->napi); > - > - /* Disable furthur irq's > - (msix not enabled with napi) */ > - writel(0, base + NvRegIrqMask); > + if (napi_schedule_prep(&np->napi)) { > + /* > + * Disable further irq's (msix not enabled with napi) > + */ > + writel(0, base + NvRegIrqMask); > + __napi_schedule(&np->napi); > + }
Yes, good catch. There is a race condition here with napi poll.
I would prefer to do the following to keep the code simple and clean.
writel(0, base + NvRegIrqMask); napi_schedule(&np->napi);
.....
> > #else > do > @@ -3615,12 +3617,13 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data) > nv_msi_workaround(np); > > #ifdef CONFIG_FORCEDETH_NAPI > - napi_schedule(&np->napi); > - > - /* Disable furthur irq's > - (msix not enabled with napi) */ > - writel(0, base + NvRegIrqMask); > - > + if (napi_schedule_prep(&np->napi)) { > + /* > + * Disable further irq's (msix not enabled with napi) > + */ > + writel(0, base + NvRegIrqMask); > + __napi_schedule(&np->napi); > + } > #else > do > { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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