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Florian Westphal authored
retain last used xfrm_dst in a pcpu cache. On next request, reuse this dst if the policies are the same. The cache will not help with strict RR workloads as there is no hit. The cache packet-path part is reasonably small, the notifier part is needed so we do not add long hangs when a device is dismantled but some pcpu xdst still holds a reference, there are also calls to the flush operation when userspace deletes SAs so modules can be removed (there is no hit. We need to run the dst_release on the correct cpu to avoid races with packet path. This is done by adding a work_struct for each cpu and then doing the actual test/release on each affected cpu via schedule_work_on(). Test results using 4 network namespaces and null encryption: ns1 ns2 -> ns3 -> ns4 netperf -> xfrm/null enc -> xfrm/null dec -> netserver what TCP_STREAM UDP_STREAM UDP_RR Flow cache: 14644.61 294.35 327231.64 No flow cache: 14349.81 242.64 202301.72 Pcpu cache: 14629.70 292.21 205595.22 UDP tests used 64byte packets, tests ran for one minute each, value is average over ten iterations. 'Flow cache' is 'net-next', 'No flow cache' is net-next plus this series but without this patch. Signed-off-by:
Florian Westphal <fw@strlen.de> Signed-off-by:
David S. Miller <davem@davemloft.net>
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