In D59708#1370145, @markj wrote:

In D59708#1370131, @tuexen wrote:

I think the reason for per VNET zones might have been to protect against the case where a service running in one VNET cannot run the services running in other VNETs out of resources. However, that would require per VNET limits and would need to require that this isolation is done for all resources, which doesn't seem to be the case.

Right, that is one legitimate use for per-VNET zones. In the long term, UMA itself should perhaps provide this functionality, rather than forcing consumers to create separate zones.

I think the reason for per VNET zones might have been to protect against the case where a service running in one VNET cannot run the services running in other VNETs out of resources. However, that would require per VNET limits and would need to require that this isolation is done for all resources, which doesn't seem to be the case.

In D59450#1363646, @glebius wrote:

In D59450#1363624, @tuexen wrote:

I like the idea of increasing the MTU. Is there a reason why you select 0xffff? This is the maximum size of an IPv4 packet, but an IPv6 packet can have a size of 0xffff + 40. Why not use that value? Would it make sense to use a multiple of 4?

I didn't measure, but speculatively I decided that it would be better to have it a multiple of PAGE_SIZE rather than multiple + tiny. In the second case a bulk transfer would allocate an extra page (or an mbuf, if optimized) that would be underutilized.

I like the idea of increasing the MTU. Is there a reason why you select 0xffff? This is the maximum size of an IPv4 packet, but an IPv6 packet can have a size of 0xffff + 40. Why not use that value?

In D59305#1360809, @cc wrote:

In D59305#1360805, @tuexen wrote:

What about the RACK and BBR stack?

They don't seem to be impacted or relevant.

static void rack_post_recovery(struct tcpcb *tp, uint32_t th_ack);

static void bbr_post_recovery(struct tcpcb *tp);

What about the RACK and BBR stack?

Committed in c6ae11c1b0d9.

In D58594#1344809, @rscheff wrote:

Looks like you do modify the BBR/RACK stack too, unlike the high level description. In both places the same checks used to be done in a mirror image - and this again mirrors each other.

As suggested by glebius.