[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: NOHZ: local_softirq_pending 08

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.


Tilman Schmidt                    E-Mail: tilman@xxxxxxx
Bonn, Germany
Diese Nachricht besteht zu 100% aus wiederverwerteten Bits.
Ungeöffnet mindestens haltbar bis: (siehe Rückseite)

Attachment: signature.asc
Description: OpenPGP digital signature

[Linux Audio Users]     [Hams]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Photo]     [Yosemite Photos]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linux Resources]     [Fedora Users]

Powered by Linux