[ovs-discuss] max mega flow 64k per pmd or per dpcls?

[Darrell Ball]

Q: “how it is calculated in such an exact number? “

A: It is a reasonable number to accommodate many cases.

Q: “If there are more ports added for polling, for avoid competing can I increase the 64k size into a
bigger one?”

A: If a larger number is needed, it may imply that adding another PMD and dividing the forwarding
work would be best.  Maybe even a smaller number of flows may be best served with more PMDs.





On 6/29/17, 7:23 AM, "ovs-discuss-bounces at openvswitch.org on behalf of Bodireddy, Bhanuprakash" <ovs-discuss-bounces at openvswitch.org on behalf of bhanuprakash.bodireddy at intel.com> wrote:

    >
    
    >I guess the answer is now the general LLC is 2.5M per core so that there is 64k
    
    >flows per thread.
    
    
    
    AFAIK, the no. of flows here may not have to do anything with LLC.  Also there is EMC cache(8k entries) of ~4MB per PMD thread.




    
    Yes the performance will be nice with simple test cases (P2P with 1 PMD thread) as most of this fits in to LLC. But in real scenarios  OvS-DPDK can be memory bound.
    
    
    
    BTW, on my DUT the LLC is 35MB and has 28 cores and so the assumption of 2.5M/core isn't right. 
    
    
    
    - Bhanuprakash.
    
    
    
    >
    
    >On Fri, Jun 23, 2017 at 11:15 AM, Hui Xiang <xianghuir at gmail.com> wrote:
    
    >Thanks Darrell,
    
    >
    
    >More questions:
    
    >Why not allocating 64k for each dpcls? does the 64k just fit in L3 cache or
    
    >anywhere? how it is calculated in such an exact number?  If there are more
    
    >ports added for polling, for avoid competing can I increase the 64k size into a
    
    >bigger one? Thanks.
    
    >
    
    >Hui.
    
    >
    
    >
    
    
    
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