Felix Radensky writes:
> Is slab good enough in 2.4 ? I was thinking that one of the goals
> of skb-recycle patch was to avoid skb allocations and deallocations
> which consume quite a lot of CPU time (as profile shows). Are you
> saying that your patch is not hepling to reduce CPU load ?
Try to understand why/where packets get dropped in your setup to start with.
Bridging shouldn't be different from routing which I experiments with.
Check /proc/interrupts, /proc/net/softnet_stat and check for drops at
qdisc ( "tc -s qdisc" you might have to readd the qdisc just get the stats)
Possible your TX-side cannot keep up with RX. Often the TX ring is not
cleard aggressivly enough at high rates due intr. mitigation etc or possibly
HW_FLOWCTRL from sink device. Disable it in your for testing.
When you cure the cause in-kernel-drop you should have packets drops
on the DMA-ring (in the driver) with NAPI drivers and no unnecssary
skb allocation/CPU use or DMA's.
> echo 1 > /proc/irq/48/smp_affinity
> to avoid this kind of problem, or something else is required ?
If you have both both incoming and outgoing on same CPU there will
be no cache bouncing of course and a UP kernel would be faster if this
all your job.
Cheers.
--ro
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