lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 29 Oct 2012 00:23:04 +0100
From:	Javier Domingo <>
Subject: Re: Information about napi_struct and net_device

Hi all,

I am going to read all the netdevice.h declarations, and try to obtain
a more general view about what does each function do. At the moment,
I've read the page Rami Rosen [1] told be about, but there isn't the
explanation I was looking for, but had links to the netdev conferences
from the past years, and I read many of them.

I wish to ask/state a few questions/words about the napi_struct
creation etc. correct me please if I'm wrong

    1. napi_struct has the fields that usually had net_device about
all control about the polling, so that the device structure where each
driver puts its functions is now much cleaner. With this, though you
have the particular net_device struct it uses in the napi_struct, you
can make as if they would be separated [3].

          a. I need to work with net_device, but I also need to work
with napi_struct, I found these lines of code:
		 *	Some hardware also needs these fields, but they are not
		 *	part of the usual set specified in Space.c.

			unsigned long		state;

		struct list_head	dev_list;
		struct list_head	napi_list;
		struct list_head	unreg_list;

              inside of the net_device structure, I know I can take
the net_device pointer as documented in [3], but how may  I obtain the
napi_struct from the netdevice? or I am doing it the wrong way?

    2. I found what napi GRO was in a David S. Miller blog post [2],
which explains many things I found about GRO, that it is about
improving packet processing in the network stack functions.

Javier Domingo


2012/10/28 Eric Dumazet <>:
> On Sat, 2012-10-27 at 20:22 +0200, Francois Romieu wrote:
>> Not all drivers use napi_gro_receive/napi_gro_flush.
> Yes, note that I only mentioned "grep napi", not these specific verbs
> Also, napi_gro_receive() could be used now GRO doesnt mandate hardware
> checksums.
>> It could be worth comparing with drivers/net/ethernet/via/via-rhine.c (small)
>> or drivers/net/ethernet/broadcom/tg3.c (bigger).
> Unfortunately tg3.c uses internal stuff sith napi substring, so I
> ignored it :
> $ grep napi drivers/net/ethernet/broadcom/tg3.c | wc -l
> 376
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists