Re: [PATCH RT] net: move xmit_recursion to per-task variable on -RT

From: Hannes Frederic Sowa
Date: Thu Jan 14 2016 - 18:00:48 EST


On 14.01.2016 23:20, Eric Dumazet wrote:
On Thu, 2016-01-14 at 23:02 +0100, Hannes Frederic Sowa wrote:

We are just adding a second recursion limit solely to openvswitch which
has the same problem:

https://patchwork.ozlabs.org/patch/566769/

This time also we depend on rcu_read_lock marking the section being
nonpreemptible. Nice would be a more generic solution here which doesn't
need to always add something to *current.


Note that rcu_read_lock() does not imply that preemption is disabled.

Exactly, it is conditional on CONFIG_PREEMPT_CPU/CONFIG_PREMPT_COUNT but haven't thought about exactly that in this moment.

I will resend this patch with better protection.

Thanks Eric!