queue buffer size increasing howto?

Banszki Gabor banszki.gabor at chello.hu
Sat Sep 4 10:16:14 CEST 2004

Hi Everybody!

Thank for answer of Tobias!!

I could get the buffer size by the getsockopt (107520).

After this I was able to increase the size of buffer to 215040 by your

   int size, size_len;
   size_len = sizeof(size);
   rv = getsockopt (fd, SOL_SOCKET, SO_RCVBUF, &size, &size_len); 
   printf ("Oldsize of buffer: %i \n",size); { I've got 107520)

   size = 1256000;
   rv = setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &size, size_len); 

   rv = getsockopt (fd, SOL_SOCKET, SO_RCVBUF, &size, &size_len); 
   printf ("New size of buffer: %i \n",size); ( I've got 215040 )

After this I can see the same situation with this command....

 watch -n 0 "cat /proc/net/ip_queue"

...like earlier... 
The maximum number is around 252 - 258, and I still get the netlink
error message "No buffer space....."

I think it didn't help... Why?
Maybee I should increase the SO_RCVBUF by more? But how?



On Sun, 2004-08-22 at 16:50, Tobias DiPasquale wrote:
> On Sun, 22 Aug 2004 15:40:16 +0200, Banszki Gabor
> setsockopt(2):
> int fd, rv, size = LARGE_SOCKET_BUFFER;
> rv = setsockopt( fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof( size));
> ...
> > With this command: watch -n 0 "cat /proc/net/ip_queue" during my
> > application running the biggest number of "Queue length" is 255.
> > 
> > I don't understand it, because the "Queue max. length" is 2048.
> See above. You should be able to increase the size of the socket
> receive buffer in your userspace process without changing the length
> of ip_queue's internal packet queue, but test that out to make sure.
> You will probably need to run the process with root privileges to
> change your socket receive buffer size, however.

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