| Message ID | 20091015114052.GA9870@ff.dom.local |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
Jarek Poplawski wrote, On 10/15/2009 01:40 PM: > On 12-10-2009 13:25, Tilman Schmidt wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> On Mon, 12 Oct 2009 03:32:46 -0700 (PDT), David Miller wrote: >>> The PPP receive paths in ppp_generic.c do a local_bh_disable()/ >>> local_bh_enable() around packet receiving (via ppp_recv_lock()/ >>> ppp_recv_unlock() in ppp_do_recv). >>> >>> So at least that part is perfectly fine. >>> >>> ppp_input(), as called from ppp_sync_process(), also disables BH's >>> around ppp_do_recv() calls (via read_lock_bh()/read_unlock_bh()). >>> >>> So that's fine too. >>> >>> Do you have a bug report or are you just scanning around looking >>> for trouble? :-) >> I have encountered the message in the subject during a test of >> the Gigaset CAPI driver, and would like to determine whether >> it's a bug in the driver, a bug somewhere else, or no bug at >> all. The test scenario was PPP over ISDN with pppd+capiplugin. >> In an alternative scenario, also PPP over ISDN but with >> smpppd+capidrv, the message did not occur. >> >> Johannes' answer pointed me to the netif_rx() function. >> The Gigaset driver itself doesn't call that function at all. >> In the scenario where I saw the message, it was the SYNC_PPP >> line discipline that did. But from your explanation I gather >> that the cause cannot lie there. >> >> So now I'm looking for other possible causes of that message. BTW, it seems calling napi_schedule() from process context should trigger such a warning too. Jarek P. > > Anyway, I agree with Michael Buesch there is no reason to waste time > for tracking all netif_rx vs netif_rx_ni uses, and it seems we could > avoid it by using the "proper" version of raise_softirq_irqoff() in > __napi_schedule(). Could anybody try if I'm not wrong? > > Thanks, > Jarek P. > --- > > net/core/dev.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index 28b0b9e..7fc4009 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -2728,7 +2728,7 @@ void __napi_schedule(struct napi_struct *n) > > local_irq_save(flags); > list_add_tail(&n->poll_list, &__get_cpu_var(softnet_data).poll_list); > - __raise_softirq_irqoff(NET_RX_SOFTIRQ); > + raise_softirq_irqoff(NET_RX_SOFTIRQ); > local_irq_restore(flags); > } > EXPORT_SYMBOL(__napi_schedule); > -- > To unsubscribe from this list: send the line "unsubscribe linux-ppp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 15.10.2009 19:53 Jarek Poplawski wrote: > Jarek Poplawski wrote, On 10/15/2009 01:40 PM: > >> On 12-10-2009 13:25, Tilman Schmidt wrote: >>> I have encountered the message in the subject during a test of >>> the Gigaset CAPI driver, and would like to determine whether >>> it's a bug in the driver, a bug somewhere else, or no bug at >>> all. The test scenario was PPP over ISDN with pppd+capiplugin. >>> In an alternative scenario, also PPP over ISDN but with >>> smpppd+capidrv, the message did not occur. I'm sorry, I had confused the two cases. The message occurs in the smpppd+capidrv scenario, not with pppd+capiplugin. >>> Johannes' answer pointed me to the netif_rx() function. >>> The Gigaset driver itself doesn't call that function at all. >>> In the scenario where I saw the message, it was the SYNC_PPP >>> line discipline that did. This analysis was therefore wrong. It would be the netif_rx() call towards the end of isdn_ppp_push_higher() in drivers/isdn/i4l/isdn_ppp.c L1177. >> Anyway, I agree with Michael Buesch there is no reason to waste time >> for tracking all netif_rx vs netif_rx_ni uses, and it seems we could >> avoid it by using the "proper" version of raise_softirq_irqoff() in >> __napi_schedule(). Could anybody try if I'm not wrong? >> >> net/core/dev.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/net/core/dev.c b/net/core/dev.c >> index 28b0b9e..7fc4009 100644 >> --- a/net/core/dev.c >> +++ b/net/core/dev.c >> @@ -2728,7 +2728,7 @@ void __napi_schedule(struct napi_struct *n) >> >> local_irq_save(flags); >> list_add_tail(&n->poll_list, &__get_cpu_var(softnet_data).poll_list); >> - __raise_softirq_irqoff(NET_RX_SOFTIRQ); >> + raise_softirq_irqoff(NET_RX_SOFTIRQ); >> local_irq_restore(flags); >> } >> EXPORT_SYMBOL(__napi_schedule); I have tested your patch and I can confirm that it fixes the messages. I have not noticed any ill effects. Thanks, Tilman
diff --git a/net/core/dev.c b/net/core/dev.c index 28b0b9e..7fc4009 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2728,7 +2728,7 @@ void __napi_schedule(struct napi_struct *n) local_irq_save(flags); list_add_tail(&n->poll_list, &__get_cpu_var(softnet_data).poll_list); - __raise_softirq_irqoff(NET_RX_SOFTIRQ); + raise_softirq_irqoff(NET_RX_SOFTIRQ); local_irq_restore(flags); } EXPORT_SYMBOL(__napi_schedule);