[dpdk-dev] DPDK LPM table thread safety

Shyam Sundar Govindaraj ssgovind at Brocade.com
Thu May 21 19:51:34 CEST 2015


Hi

  I am interested in DPDK LPM implementation. I understand the high performance of this LPM table but, when it comes to multithreaded application, I read the following safety issue in DPDK documentation. I understand that multithread read and multithread write are not possible without locking table. But I want to know if single thread write and multithread read are possible with your implementation without any locking mechanism.

20. Thread Safety of DPDK Functions
"The hash and LPM libraries are, by design, thread unsafe in order to maintain performance. However, if required the developer can add layers on top of these libraries to provide thread safety. Locking is not needed in all situations, and in both the hash and LPM libraries, lookups of values can be performed in parallel in multiple threads. Adding, removing or modifying values, however, cannot be done in multiple threads without using locking when a single hash or LPM table is accessed. Another alternative to locking would be to create multiple instances of these tables allowing each thread its own copy".
http://dpdk.org/doc/guides/prog_guide/thread_safety_intel_dpdk_functions.html

Thanks
Shyam


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