Re: [PATCH net-next] net: ethtool: Don't check if RSS context exists in case of context 0

From
Jakub Kicinski <kuba@kernel.org>
Date
2025-02-27 15:29:34
Reply to
Edward Cree, 2025-02-27
On Thu, 27 Feb 2025 15:18:47 +0000 Edward Cree wrote:
On 27/02/2025 04:45, Jakub Kicinski wrote:
quoted
The ordering guarantees of ntuple filters are a bit unclear.
My understanding was that first match terminates the search,
actually, so your example wouldn't work :S  
My understanding is that in most ntuple implementations more-
 specific filters override less-specific ones, in which case
 Gal's setup would work.
The behavior of partially overlapping rules being undefined?
On other implementations which use the rule number as a
 position (like the API/naming implies) you could insert the
 5-tuple rule first and that would work too.
quoted
Oh, I think Ed may tell us that using context 0 + queue offset is legit.  
I hadn't actually thought of that, but yes that's true too.

Anyway, 'mechanism, not policy' says we should allow ctx 0
 unless there's some mechanism reason why it can't be
 supported, and I don't see one.
I never uttered the thought that lead me to opposing. 
ctx 0 is a poor man's pass / accept. If someone needs a pass we should
add an explicit "action pass". Or am I missing something magical that
ctx 0 would do that's not 100% the same as pass (modulo the queue
offset)? Using ctx 0 as implicit pass is a very easy thing to miss
for driver developers.

But yeah, the queue offset is legit.
Thread (16 messages) 16 messages, 4 authors, last reply 2025-03-04
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help