lkml.org 
[lkml]   [2008]   [Apr]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] soft lockup rose_node_list_lock
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.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-hams" 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 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/

\
 
 \ /
  Last update: 2008-04-21 22:35    [W:0.068 / U:0.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site