Re: iSCSI read/write cost difference

[mingz <mingz@ele.uri.edu>]

sorry for spam. i already solve this EFAULT problem. I will post new results 
once I get them.

>
> I think the UNH iSCSI implementation dosen't set TCP_NODELAY on the
> connection sockets, which can lead to strange performance characteristics
> like this.  See the man pages for "setsockopt" and "tcp".  You can find an
> example of setting TCP_NODELAY in the linux-iscsi drivers at
> http://sourceforge.net/projects/linux-iscsi.  Just download the source and
> grep for TCP_NODELAY.
yes, it doesn't set the TCP_NODELAY. I read the linux-iscsi code and try to 
add this sock->ops->setsockopt() in UNH code. But it always return EFAULT 
indicating a bad address. but i use a similar way to define arg = 1 as a 
local variable. i am not sure why i am wrong. and i check the 
inet_set_sockopt and tcp_setsock_opt, nowhere return a EFAULT.

can some one figure it out? thx.




>
> Anthony J. Battersby
> Cybernetics

-- 
 --------------------------------------------------
| Ming Zhang, PhD. Student                                     
| Dept. of Electrical & Computer Engineering       
| College of Engineering                           
| University of Rhode Island                       
| Kingston RI. 02881                                  
| e-mail: mingz@ele.uri.edu                        
| Tel. (401) 874-2293 Fax  (401) 782-6422          
| http://www.ele.uri.edu/~mingz                     
 --------------------------------------------------