RE: 8xx_io/enet.c

Hi,

-----Original Message-----
From: Joakim Tjernlund [mailto:joakim.tjernlund@lumentis.se]
Sent: Dienstag, 10. Dezember 2002 16:47
To: Stephan Linke
Subject: RE: 8xx_io/enet.c

quoted

Hi,

just checked the mailing list for the patches. Looks like you

mean the 'copy

quoted

large buffers' patch.
I took the second version and applied it to fec.c too.
It works fine on both devices. The only thing that confused me was the
discussion about the possibility of inconsistent data.

Thats the one. However there is a small bug in version 2 w.r.t when the
invalidate_dcache_range call is made. In the second version the
call is made
AFTER the buffer has been received as opposed in my first version
where the
call is made BEFORE handing over the buffer to the CPM. That may in some
rare case corrupt the packet. See
http://lists.linuxppc.org/linuxppc-embedded/200211/msg00120.html

This is only relevant for 8xx, 82xx don't have to invalidate.

quoted

But we didn't noticed
any performance impact when testing it with IP packets.

Didn't you get any performace increase after appling my patch?
If you did, could you send me your performace numbers?
Did you try the first version also? If so,any performance
difference compared with version 2?

  Jocke

Indeed we had a better performance with the patch applied to fec.c
(100base-Tx). Unfortunately I don't have the results at the moment. At
enet.c I didn't noticed mutch of a difference since handling 10base-T
traffic isn't that mutch of a problem at the moment and I didn't spend time
to figure out the exact CPU load.
I remember that someone said he had an performance impact at small packets.
I didn't noticed any (even though there must be a slight on caused by the
additinal if-statement).
I can post some of our results results after I did some more tests but that
may take a while since I am buisy with other stuff at the moment.


  Stephan

PS.
   Any perticular reason not to cc the embedded list also? Others would
   probably be intressted also.

Well, there is a 'reason'. I simply didn't payed attention to the fact that
a simple reply doesn't reply to the list.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/