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VK7AX > LINHAM 22.04.08 02:02l 83 Lines 3217 Bytes #999 (0) @ WW
BID : VK7AX-2204LA
Read: GUEST
Subj: Re: [PATCH] soft lockup rose_node_list_lock
Path: IZ3LSV<IQ0LT<IK2XDE<ON4HU<DB0RES<DK0WUE<7M3TJZ<CX2SA<VK7NW
Sent: 080422/0103Z @:VK7NW.#ULV.TAS.AUS.OC #:43802 [NWTARIG] FBB7.00g $:VK7AX-2
From: VK7AX@VK7NW.#ULV.TAS.AUS.OC
To : LINHAM@WW
From: Bernard Pidoux <pidoux@ccr.jussieu.fr>
Date: Mon, 21 Apr 2008 22:27:27 +0200
To: David Miller <davem@davemloft.net>
CC: ralf@linux-mips.org, linux-kernel@vger.kernel.org, linux-hams@vger.kernel.org, Linux Netdev List <netdev@vger.kernel.org>
Hi David,
I also spent a lot of time to understand how rose behaved and I agree that it is difficult to decifer a code especially dealing
with socket programming and when it was written by someone else.
But as a radioamateur, Linux is a hobby for me and I like to learn.
Actually, rose_get_neigh() is called when two different events are occuring :
- first, it is called by rose_connect() in order to find if an adjacent node is ready to route to a specific ROSE address.
- second, rose_route_frame() calls rose_get_neigh() every time an incoming frame must be routed to an appropriate AX25 connection.
By the way, rose_get_neigh() function is not optimized for it does not check if an adjacent node is already connected before a new connect is requested.
For this purpose I have derived a new function, I named rose_get_route(), that is called by rose_route_frame() to find a route via an adjacent node.
This function has been tested for months now and it works fine.
It adds the automatic frames routing that rose needed desperately.
I will send next a patch with this new rose_get_route().
Bernard Pidoux
p.s. my email client is set for MIME attachements, but it seems corrupted.
I will fix that. Sorry for the unvoluntary increase of workload it gave you.
David Miller a écrit :
> From: Bernard Pidoux <pidoux@ccr.jussieu.fr>
> Date: Sun, 20 Apr 2008 19:09:23 +0200
>
>
>> Since rose_route_frame() does not use rose_node_list we can safely
>> remove rose_node_list_lock spin lock here and let it be free for
>> rose_get_neigh().
>>
>> Signed-off-by: Bernard Pidoux <f6bvp@amsat.org>
>>
>
> Indeed, I went over this code several times and I can't
> see any reason for rose_route_frame() to take the node
> list lock.
>
> Patch applied, thanks Bernard. But one thing...
>
>
>> diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c
>> index fb9359f..5053a53 100644
>> --- a/net/rose/rose_route.c
>> +++ b/net/rose/rose_route.c
>> @@ -857,7 +857,6 @@ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25)
>> src_addr = (rose_address *)(skb->data + 9);
>> dest_addr = (rose_address *)(skb->data + 4);
>>
>> - spin_lock_bh(&rose_node_list_lock);
>> spin_lock_bh(&rose_neigh_list_lock);
>> spin_lock_bh(&rose_route_list_lock);
>>
>>
>
> Could you please fix your email client so it doesn't corrupt
> patches like this? I've had to apply all of your patches by
> hand because the tabs have been converted into spaces. Use
> MIME attachments if you have to.
>
> Thanks again.
--
**************************************************************************
ABOVE IS A CROSS POST TO THE PACKET RADIO NETWORK IN AN ATTEMPT TO PROMOTE
FURTHER INTEREST IN HAM SOFTWARE USING LINUX OPERATING SYSTEMS & PACKET RADIO
Courtesy Tony VK7AX VK7AX@VK7NW.#ULV.TAS.AUS.OC
**************************************************************************
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