Messages in this thread | | | Subject | Re: [RFC PATCH 0/2] net: threadable napi poll loop | From | Hannes Frederic Sowa <> | Date | Thu, 12 May 2016 00:47:29 +0200 |
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On 11.05.2016 16:45, Eric Dumazet wrote: > On Wed, May 11, 2016 at 7:38 AM, Paolo Abeni <pabeni@redhat.com> wrote: > >> Uh, we have likely the same issue in the net_rx_action() function, which >> also execute with bh disabled and check for jiffies changes even on >> single core hosts ?!? > > That is why we have a loop break after netdev_budget=300 packets. > And a sysctl to eventually tune this. > > Same issue for softirq handler, look at commit > 34376a50fb1fa095b9d0636fa41ed2e73125f214 > > Your questions about this central piece of networking code are worrying. > >> >> Aren't jiffies updated by the timer interrupt ? and thous even with >> bh_disabled ?!? > > Exactly my point : jiffie wont be updated in your code, since you block BH.
To be fair, jiffies get updated in hardirq and not softirq context. The cond_resched_softirq not looking for pending softirqs is indeed a problem.
Thanks, Hannes
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