+ Herbert
On 3/16/2019 7:14 PM, Toke Høiland-Jørgensen wrote:
Felix Fietkau <nbd@xxxxxxxx> writes:
When using iTXQ, tx sequence number allocation and statistics are run at
dequeue time. Because of that, it is safe to enable NETIF_F_LLTX, which
allows tx handlers to run on multiple CPUs in parallel.
Cool, didn't know about that flag.
It is water under the bridge as this patch got applied already, but I
stumbled upon it just recently and didn't know about that flag either.
So I looked for more information about it and found the definition [1],
but the comment seemed important enough to send this reply.
NETIF_F_LLTX_BIT, /* LockLess TX - deprecated. Please */
/* do not use LLTX in new drivers */
Here is the commit that marked it deprecated:
commit e24eb521fbf2a350ce879dfc1d8e56d4ffa2aa22
Author: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Date: Tue Sep 25 19:42:02 2007 -0700
[NET]: note that NETIF_F_LLTX is deprecated
So I am not sure we should really do this in mac80211. Maybe Herbert can
comment although it has been over a decade ago.
Regards,
Arend
[1]
https://elixir.bootlin.com/linux/latest/source/include/linux/netdev_features.h#L32
