[dpdk-dev] [RFC PATCH 0/7] support multi-phtread per lcore

Liang, Cunming cunming.liang at intel.com
Mon Dec 22 02:51:27 CET 2014


...
> I'm conflicted on this one. However, I think far more applications would be
> broken
> to start having to use thread_id in place of an lcore_id than would be broken
> by having the lcore_id no longer actually correspond to a core.
> I'm actually struggling to come up with a large number of scenarios where it's
> important to an app to determine the cpu it's running on, compared to the large
> number of cases where you need to have a data-structure per thread. In DPDK
> libs
> alone, you see this assumption that lcore_id == thread_id a large number of
> times.
> 
> Despite the slight logical inconsistency, I think it's better to avoid introducing
> a thread-id and continue having lcore_id representing a unique thread.
> 
> /Bruce

Ok, I understand it. 
I list the implicit meaning if using lcore_id representing the unique thread.
1). When lcore_id less than RTE_MAX_LCORE, it still represents the logical core id.
2). When lcore_id large equal than RTE_MAX_LCORE, it represents an unique id for thread.
3). Most of APIs(except rte_lcore_id()) in rte_lcore.h suggest to be used only in CASE 1)
4). rte_lcore_id() can be used in CASE 2), but the return value no matter represent a logical core id.

If most of us feel it's acceptable, I'll prepare for the RFC v2 base on this conclusion.

/Cunming


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