Re: [PATCH net 1/2] net/sched: pfifo_fast: cap ring size and account to memcg

On Sat, Aug 22, 2026 at 4:44 PM Jakub Kicinski [off-list ref] wrote:

On Thu, 20 Aug 2026 05:57:41 -0400 Jamal Hadi Salim wrote:

quoted

+     if (qlen > 65535) {
+             pr_warn_ratelimited("pfifo_fast: capping ring size %u to 65535 for dev %s\n",
+                                 qlen, qdisc_dev(qdisc)->name);
+             qlen = 65535;
+     }

Why not a hard cap?

sorry, where to put the hard cap and what would it be?
Or maybe you misspoke and intended to say "why put a hardcap"?

Or maybe in this case probably safer to just reject the change if > hard cap?

cheers,
jamal

We do that all over the place, once in a release we
pick a value too small and someone quickly sends us a fix up to bump
the number. No problem.